Abstract: Collections and identifications of aquatic insects in Huaxi stream of Zhejiang province were conducted twice during June-July and September-October of 2016. The water quality of the stream was assessed by 5 indicators such as species richness index (dM), EPT index, Beck’s biotic index (BI), family biotic index (FBI). The results showed that dM, BI, FBI and stream invertebrate grade number-average level was 23.32, 101, 2.8 and 6.43 respectively, and the water quality was excellent or good and healthy. The EPT index was 32, and the water quality was second grade. The results of biotic index analysis suggested that water quality of the stream was good.