1992: May 14-17, the 7 th CCES-TUWB congress and Academic Seminar on Xidan Station Project of Beijing Metro were held in Beijing. Totally 421 representatives attended the event, including CCES-TUWB council members, paper authors and other experts. In the congress, 145 papers were received, of which 101 papers were accepted in paper collection, and 11 papers were selected as excellent papers. 12 experts delivered lectures in the event. 
 　　 1995: Feb. 26 –Mar. 11, invited by Japan Sino-Japan Economy Association, a 6-person delegation headed by CCES-TUWB president Xuanyuan Xiaowen paid a visit to Japan, from which, their practical experience in underground engineering was enriched.
 　　 1996: Apr. 20-24, entrusted by CCES, a 3-person delegation headed by Xuanyuan Xiaowen, vice general manager, CREC participated in the 22 nd ITA general assembly (Tunnel North America 1996) held in Washington, USA. Totally 854 scientific experts participated in the scientific seminar. Mr. Wang Jianyu was appointed as the correspondent of ITA. 
 　　 Oct. 13-16, the 9 th CCES-TUWB congress and seminar were held in Beijing. More than 200 representatives participated in the event. Mr. Su Yongfu, Vice minister of MOR and Xu Ronglie, president of CCES-TUWB delivered keynote speeches. In the congress, more than 120 papers were received, of which 86 papers were accepted in paper collection.