With chenodeoxycholic acid as starting material,a series of lactam derivatives of chenodeoxycholic acid was synthesized and their antiproliferative activities against some cancer cells were determined.Among the synthesized derivatives,compounds 6 and 18 displayed distinct antiproliferative activity against PC-3,H-292,SKBR3 and Hey-1B cancer cells,and compounds 10,17 and 18 showed significant antiproliferative activity against SKBR3 cells.Our results reveal that the position of hydroximino on ring A or B of the parental scaffold dramatically affects the antiproliferative activity of these compounds.The conversion of 7-hydroximino to other substituent or 7-hydroximino to 3-hydroximino in the compounds resulted in a dramatic decrease of the antiproliferative activity,suggesting the importance of 7-hydroximino group for the biological activity of the compounds.The structure/activity correlation generated from the studies provides valuable information for the further design of novel chemotherapeutic drugs.