Objective:To investigate the antitumor activity of the compound HS-4 and the action mechanism.Methods:MTT method was used to test in vitro antitumor activity of the compound HS-4.Orthotopic xenotransplantation tumor model of liver cancer was established in nude mice,and.in vivo antitumor activity of compound HS-4 was tested with a small animal in-vivo imaging system.Sequencing of small RNA library and RNA library was performed in HS-4 treated tumor cell group and control group to investigate the anti-cancer mechanism of HS-4 at level of functional genomics,using high-throughput sequencing technology.Results:HS-4 was found to have relatively high in-vitro antitumor activity against liver cancer cells,gastric cancer cells,renal cancer cells,lung cancer cells,breast cancer cells and colon cancer cells.The IC_(50) values against SMMC-7721 and Bel-7402 of liver cancer cells were 0.14 and 0.13 nmol/L respectively,while the IC_(50) values against MGC-803 and SGC-7901 of gastric cancer cells were 0.19 and 0.21 nmol/L,respectively.It was demonstrated that HS- 4 possessed a betler therapeutic effect in liver cancer.Conclusions:A new reliable orthotopicxenotransplantation tumor model of liver cancer in nude mice is established.The new compounds HS-4 was found to possess relatively high in vivo and in vitro antitumor activity against liver cancer cells.