A　series　of　new　emodin　derivatives　modified　at　the　C-3　and　the　C-6　positions　were　synthesized,　and　evaluated　for　their　anticancer　activities　in　vitro　and　in　vivo.　Among　them,　Compounds　5g　and　5h　had　more　significant　antiproliferative　ability　against　HepG2,　BGC-823,　AGS　cancer　cell　lines　and　low　cytotoxicity　to　HELF　normal　cell　line,　respectively.　Compounds　5g　and　5h　induced　AGS　cell　cycle　arrest　at　G0/G1　phase　and　induce　apoptosis　via　activation　of　caspase-3　and　caspase-9　enzyme.　In　vivo　studies　using　H22　xenografts　in　Kunming　mice　were　conducted　with　5g　and　5h.　The　results　revealed　that　the　medium　dosage　group　(10　mg/kg)　of　5g　and　the　high　dosage　group　(25　mg/kg)　of　5h　showed　significant　antitumor　activity　compared　to　the　control　group.　(C)　2012　Elsevier　Masson　SAS.　All　rights　reserved.