In order to optimize the conditions of microwave assisted extraction of polysaccharides from Enteromorpha intestinals, the effect of 5 factors including microwave power, including the extraction duration, temperature, times of extraction and solid/liquid ratio on the extraction yield, which was investigated by the single factors in experiment. The extraction conditions were further optimized by the response surface methodology with the Design-Expert 8.0.5 software. The results showed that their effects were in the order of temperature > microwave power > times of extraction > extraction duration. The optimal extraction conditions of microwave assisted extraction of polysaccharides from E. intestinals were determined as followed: microwave power 500 W, extraction duration 15 min, temperature 90 ℃, extracting 2 times, solid/liquid ratio of 130 (g/mL). Under these optimal conditions, the experimental yield was 11.38% with polysaccharides content of 31.34%. It provides a reference in the research of extraction technology of E. intestinals polysaccharides.