Abstract: In this paper, the susceptibility to pine disease between tissue culture plantlet and seedling of P. thunbergii were compared. Meanwhile, growth traits were under inverstigation. The results showed that: for growth traits, the tissue culture plantlet grew slower,but it grew faster and had higher rate of tillering than seedling 6 months later. Furthermore, it had serious phenomenon of incline when compared to seedling. The root was stronger and lateral root developed better on 2yearold tissue culture plantlet than on seedling. In susceptibility,the susceptibility of tissue culture plantlet was a little higher than seedling. The susceptible symptoms of tissue culture plantlet appeared earlier,and its infection rate was 1—2 times higher than seedling at the same developmental stage,thus changed more evidently. Moreover,seedling could keep at a low susceptible level for a long time. There was no obvious correlation between the generations and susceptibility for tissue culture plantlets.