From 2014 to 2015, set deep plowing with straw returning (DR) and rotary tillage with straw returning (RR), took rotary tillage without straw returning (CK) as the control, studied effect of current year and the following year with straw returning on soil available nutrients and microbial biomass under different tillage methods at Plain of Xi Liao River. The results showed that deep tillage with straw returning and rotary tillage with straw returning all could increase in various degrees of soil available nitrogen, potassium content and bacteria, fungi, actinomycetes number, straw returning with deep plowing had more obvious effect, the rotary tillage with straw returning had little effect on soil available phosphorus content. Straw returning the following year, according to average for 3 different soil layers at full ripe stage, compared with CK, the content of available nitrogen in DR and RR increased by 26.60% and 16.34% respectively, available phosphorus increased by 19.81% and 0.92%, available potassium increased by 23.95% and 12.53%, according to total of 3 different soil layers, the number of bacteria increased by 36.46% and 9.8%, the number of fungi increased by 22.10% and 21.90%, the number of actinomycetes increased by 23.55% and 17.38%. Compared with the current year and the following year, the growth rate of soil available nutrient was higher than that in the current year at jointing stage, and the growth rate of other periods was higher than that in the following year, the microbial biomass performance for the following year growth rate was higher than that in the current year. Compared with the control, the soil available nutrients and microbial biomass increased mainly in the 0—10 cm soil layer. Compared with the different growth stages, the soil available nutrients performance for full ripe stage was the biggest at the current year, and the following year at the jointing stage was the biggest.