Abstract: Organic carbon and nutrient release characteristics of different Astragalus sinicus manure use levels applied at the bloom stage in a single cropping region of subtropical China were studied using manured soil in net bags with a field moisture capacity of 70% and at ambient temperature. The speed of decomposition reached a peak within 20 days, but was low after the 60th day. On the 90th day, accumulated decomposition rates of dry material represented low (equated to 15 000 kg/ha) to high (equated to 45 000 kg/ha) manure use levels were 78.7%, 76.0% and 71.2%, respectively. Release of C, N, P, and K could be calculated with the following power function formulas: Y=13.4246X^0.4391 (P<0.01), Y=14.0314X^0.4208 (P<0.01), Y=3.5458X^0.7037 (P<0.01), Y=15.7784X^0.4213 (P<0.01). Accumulated release rates of carbon and nutrient were: K>C>N>P in the first 20 days as well as during all decomposition periods. Moreover, accumulated release rates of carbon and nutrient both steadily decreased with an increase of A. sinicus manure levels.