Loulan is an important kingdom in the history of the western regions. Whether from the history of the relationship between western regions and the Central Plains Dynasty or from the position in cultural exchange between the East and the West， Loulan plays an extremely important role that has attracted broad academic attention for a long time. Loulan is one of the great powers in the western regions that completely vanished due to changes in natural conditions. For today's academia， especially scholars in archaeology， geography， environment， history， climate， and other disciplines who are highly concerned about the impact of the ecological environment on human beings， Loulan is a very attractive topic that triggered many scholars at home and abroad to put in great efforts for many years， making Loulan an ongoing hot topic in the international arena.

The study of Loulan in the modern sense begins with the archaeological excavation of Loulan by Swedish explorer Sven Hedin in 1900. Between 1904 and 1907， he compiled the eight-volume Scientific Results of a Journey in Central Asia 1899--1902， which sparked the interest of both general readers and professional scholars on the topic of Loulan and Lop Nor. In 1906， British archaeologist Aurel Stein went to Loulan and systematically investigated and excavated most of the city sites and tombs in Loulan before the speculated arrival of other expeditions. In 1912， he first published a two-volume personal travelogue， Ruins of Desert Cathay; then in 1921， he published a five-volume official archaeological report， Serindia： Detailed Report of Explorations in Central Asia and Westernmost China. In fact， there was no way he could have pocketed all of Loulan's treasures， and in 1909， not long after his departure， Zuicho Tachibana of the Japanese Otani expedition team excavated the ancient city of Loulan and obtained the \"Documents written by Li Bai\"， which proved the location of Haitou and Loulan. Subsequently， Stein went there again in 1914 and obtained new findings. From 1927 to 1935， during the Sino-Swedish Expedition to the northwest of China， Chinese team member Huang Wenbi unearthed Han Dynasty wooden journals at the Tuyin site， and Swedish team member Bergman unearthed a prehistoric cemetery at the Xiaohe site， both of which were very important archaeological discoveries. After that， the archaeological excavation work of Loulan was interrupted.

For a long time， there were not many scholars who really had a voice in Loulan， because most scholars were not personally involved or physically present. Even if they had been to Loulan， few people were able to engage in excavations. In 1980， Mr. Hou Can of the Institute of Archaeology at the Xinjiang Academy of Social Sciences was struck by luck. It was a time when Sino-Japan diplomacy was first normalized， and when NHK of Japan proposed to enter Loulan to film about the Silk Road， their request was approved by Chinese State leaders. After surveying the area， Hou Can led an archaeological team into Loulan in April of that year to carry out a formal archaeological investigation and excavation of Loulan and its nearby sites. As a result， he became the first archaeologist in Xinjiang to engage in Loulan archaeology ever since the Sino-Swedish Expedition. Moreover， the archaeological excavations in Loulan under his leadership have obtained a wealth of cultural relics and documentary materials， which have filled certain gaps in China's archaeological work and enabled Chinese scholars to have a say in the study of Loulan， while also attracting the attention of the international academic community.

After shaking off the sand and soil， Mr. Hou Can， who had returned to Urumqi， worked tirelessly and completed the Report on Archaeological Investigation and Excavation of Loulan by March 1987. This is the official report of the archaeological investigation and excavation he conducted， which gives a detailed description of the investigation and excavation process， the artifacts obtained from the archaeological excavation， and detailed analysis and research comparing against similar objects excavated by predecessors， enriched with a wealth of illustrations and texts， as well as a large number of sketches and statistical tables， reflecting his academic depth and extensive professional training in archaeology. This work can be considered an important achievement of archaeological research in the new era. However， for a number of reasons， it was never published by the time Mr. Hou Can passed away in June 2016 and remained a lifelong regret of his.

Another important area of academic achievement for Mr. Hou Can was the study of Turpan manuscripts and tomb records， and he relied on these two types of materials to conduct an in-depth study on the official positions and chronology of the Gaochang state. After I graduated in 1985， I assisted professors at Peking University in editing A Collection of Literature Research on Dunhuang and Turpan. I was asked to contact him to discuss his manuscript Newly Unearthed Turpan Epitaph after Liberation. Later， when I had the opportunity to go to Xinjiang， and when Mr. Hou Can came to Beijing， I was able to meet and learn from him. In 1990， Mr. Hou Can published the Collection of Gaochang and Loulan Studies and presented it as a gift to encourage future students.

In 1998， Mr. Hou Can retired and moved to Chengdu， but he continued to have strong emotional ties with the archaeology work in Xinjiang. He successively compiled and published three volumes of Comprehensive Collection and Deep Research on Chinese Documents from Loulan （November 1999） and two volumes of Amassing Annotations to the Tombstones Unearthed in Turpan （April 2003）. Today， we are thrilled to see the publication of his Report on Archaeological Investigation and Excavation of Loulan， which is worthy of celebration.