Duck blood plasma was treated with subcritical water under the range of temperature from 120 ℃ to 180 ℃ and the time from 0 min to 40 min. The solubility,free amino groups content and antioxidant activity of proteins were evaluated. The results showed that there were no significant differences in the solubility and free amino groups content of proteins among the samples treated with different time at 120 ℃. As the temperature was over 120 ℃,the solubility of protein decreased with the enhancement of temperature or heating time. Free amino group content deceased at 140 ℃ for 40 min. While the temperature further increased,it would increase. Antioxidant activity of original plasma protein was low,but increased apparently as the temperature or heating time increased. The DPPH radical-scavenging activity increased by 77. 08%,the reducing power increased by 39 times than original one, and the ABTS radical scavenging activity increased by 67. 65% at 180℃ for 40 min.