[Objective] The study aimed to analyze the correlation among phenological characters of Populus deltoides.[Method] The complete randomized block design was adopted and the variance of phenological characters of P.deltoides and their correlation were studied through quantifying phenological observation data and graphing.[Result] For all the plants,the ranges of flowering,germinating and defoliation were 18,18 and 31 d resp.and their average periods were 12,16 and 22 d resp.Among the 14 clones germinating ear...