Abstract: The incubating experiment was conducted to study the effects of temperature and soil moisture on decomposition of soil organic carbon in black soil with different organic carbon contents. The results show that under the same soil moisture, the CO₂ releasing rate is high at the beginning of the incubation(0～20d), and the relatively released CO₂ amount is elevated as temperature increasing. After that(＞20d), the CO₂ releasing rate is gradually becoming stable. Under the same temperature and 30%～90% of field capability, the CO₂ releasing rate is high at the beginning of the incubation (0～20d), and then decreases. And the relatively released CO₂ amount is elevated as soil water content increasing. Under same temperature and soil water condition, the CO₂ releasing rate is enhanced as the organic carbon contents increasing.