Based on China Homogenized Historical Temperature Datasets, it presents evidence for urban heat island （UHI） effects on regional temperature on a longterm scale in Northeast China, which were estimated by comparing trends of urbanrural temperature series covering two time periods of 1954—2005 and 1979—2005, respectively. Results indicate that the warming trend in Northeast China over the last 50 years is significant, and the magnitude increased for the annual mean minimum temperature is the largest（2.11 ℃）， followed by the annual mean temperature （1.59 ℃）， while the annual mean maximum temperature （1.13 ℃） is the smallest in magnitude. But the contribution of UHI is minor whenever from 1954 or 1979 to present, especially for the regional annual and winter minimum temperature, the warming attributed by UHI is only some 5%, which are both impacted mostly.