The microwave assisted extraction of phytosterol from rapeseed oil was optimized by orthogonal experiments based on single factor experiments.The results showed that under the condition of microwave temperature 50 ℃, microwave time 1 min, microwave power 200 W, the ratio of material to liquid 1∶12, the extraction amount was the highest, reaching to 2.265 mg/g. The antioxidation of the crude sterol extracted from rapeseed oil under the optimized condition was determined by studying the ability of scavenging hydroxy radicals(·OH). The result showed that crude sterol from rapeseed oil had strong antioxidant activity.