Abstract: Based on data of 1 year~3 years old seedling of Idesia polycarpa, studies were made of the standard and methods of superior seedling selection. The results showed that there were abundant genetic variations in height and diameter growth among the same age individuals, which provided material basis for choosing super seedlings. Height and basal diameter were significantly positively correlated. the choice of superior seedling depended on basal diameter increment primarily and height increment as auxiliary. From the first and the second selection, 51 superior seedlings aged 1~3 were selected by height and diameter which were no less than 1.1 times of the average amount. The selected ratio were from 0.33% to 0.39%. And superior seedlings had larger genetic gain.