Eleven　two-carbon　tethered　artemisinin-isatin　hybrids　(4a-k)　were　designed,　synthesized,　and　evaluated　for　their　antiproliferative　activity　against　MCF-7,　MDA-MB-231,　and　MDA-MB-231/ADR　breast　cancer　cell　lines,　as　well　as　cytotoxicity　toward　MCF-10A　cells　in　this　paper.　Among　them,　the　representative　hybrid　4a　(IC50:　2.49-12.6　mu　M)　was　superior　to　artemisinin　(IC50:　72.4-＞100　mu　M),　dihydroartemisinin　(IC50:　69.6-89.8　mu　M),　and　Adriamycin　(IC50:　4.46-＞100　mu　M)　against　the　three　tested　breast　cancer　cell　lines.　The　structure-activity　relationship　revealed　that　the　length　of　the　alkyl　linker　between　artemisinin　and　isatin　was　critical　for　the　activity,　so　further　structural　modification　could　focus　on　evaluation　of　the　linker.　The　in　silico　studies　were　used　to　investigate　the　mechanism　of　the　most　promising　hybrid　4a.　Target　prediction,　bioinformatics,　molecular　docking,　and　molecular　dynamics　revealed　that　the　most　promising　hybrid　4a　may　exert　anti-breast　cancer　activity　by　acting　on　multiple　targets　such　as　EGFR,　PIK3CA,　and　MAPK8　and　thus　participating　in　multiple　tumor-related　signaling　pathways.