The effects of different aeration rates on sludge composting process were studied to compost urban sewage sludge with rice straw.Variations of the main composting factors including temperature,water content,organic matters,seed germination index were determined.The difference between ventilation and nonventilation in the composting process were analyzed.Our results indicated that:(1)Proper ventilation increased the temperature,the maximum temperature was 74.20℃,the hightemperature duration was prolonged to 6 days,and the rising rate of temperature reached 24.03℃/d.(2)The water content was increased firstly,then decreased and trended to be stable.(3)At the end of composting,the organic content of 5 treatments reached the national standards.(4)Ventilation effected the seed germination index(GI),The orders of GI was treatment 3>treatment 2>treatment 1>treatment 4>treatment 5.In addition,when the aeration flowrate was 1.00 m3/h,the longest hightemperature stage(6 d)and the biggest GI(84.25%)were able to be achieved.