In order to learn situation of existing ancient Castanea mollissima trees at Huairou District of Beijing City,and provide a basis for next protecting and utilizing,a thorough investigation of existing ancient tree was developed at Jiuduhe Town in which ancient trees distribute relatively concentrated. Based on the number investigation of existing ancient tree at Jiuduhe Town of Huairou District,611 ancient trees over 100-year-old were investigated majorly through random choice. Tree height,diameter at breas...