Abstract:Abstracts:The Growth traits of 5 year old of hybrid clones of Catalpa bungei were measured and analyzed.The results showed that the growth traits including DBH(diameter at breast height),tree height,ground diameter among clones were significantly or extremely significantly different among hybrid clones;The maximum value of DBH was 5.09 cm,and the maximum value of tree height was 4.13 m, and the maximum value of ground diameter was 6.55 cm and the DBH,tree height and ground diameter growth traits were moderately controlled by heredity.Three superior clones were preliminary selected by comprehensive comparison;and the highest values of the genetic gain of the DBH,tree height were 18.55% and 13.45% respectively;and the selection rate was 13.00%.