Two new series of dihydroisoxazoline-alkyl carbon chain hybrid artemisinin analogues (artemalogs) were designed and synthesized though a 1,3-dipolar cycloaddition. Subsequent pharmacological screening led to several compounds having dramatically improved antiproliferative effects against several human tumor cell lines compared to artemisinin and dihydroartemisinin. Mechanistic studies on the most potent artemalogs were investigated.