Abstract: An in-situ experiment was carried out to study the nitrogen mineralization characters of different organic manures (chicken, pig, and cow manure) in the growth season of vegetable crop under sunlight greenhouse. The results showed that there were significant differences in the N mineralization rates among the six organic manures during the incubation period (180 days), which ranged from 1.10 to 19.09 % with average 7.5%. The mineralized nitrogen and N mineralization rate of chicken manures were the highest, followed by cow manures, while pig manures were the lowest. This might results from the higher higher C/N ratio of the chicken manure. Although no significant relationship was found between the mineralized nitrogen and the accumulated temperature of soil in each incubation period, the nitrogen mineralization tended to increase with the rising of soil temperature in Spring. The accumulated N mineralization significantly linearly correlated to the soil accumulated temperature during the whole incubation period, indicating soil temperature is a key factor affecting N mineralization of organic manures.