Abstract: In the principle of scientificalness,representativeness,operability and systematicness,11 indexes such as gradient of stem,injury degree from stem,branches,leaves,roots,plant diseases or insect pests and growing environments were chosen for evaluating 358 ancient trees distributed in Xiangshan,Qingwangfen,Mingyongling,around the second ring road and Ditan in this study.The result indicated that the trees were mainly subhealthy with a percentage of 60.89,the healthy trees were 33.80,5.31 percent trees were unhealthy and no trees were dying.According to the different places,healthy trees were the main part in Ditan and Qingwangfen with a percentage of 100 and 77.36 respectively;and sub-healthy trees were the main part in Xiangshan,around the second ring road and Mingyongling with a percentage of 87.5,81.25 and 71.96 respectively.

Key words: Beijing, ancient trees, health evaluation