Abstract: The activity of phenylalanine ammonialyase (PAL)was determined periodically during the germinating process of seeds (20-21 d, from imbibition to emergence of cotyledon) of Taiwan pine, Masson’ s pine, Japanese red pine and Japanese black pine respectively. It turned out that PAL also existed during the germination of gymnospermous seeds as well as those of angiosperm. In the case of calculation with fresh weight, all the dynamics of PAL activity in the four species appeared to be the parabola, which were similar to those of annual herbaceous crops; whereas in the case of calculation with proteinous N, all the dynamics displayed positive linear character, being different from the annual herbaceous crops which were still in parabola shape. Sequence of PAL activity from various species was similar to that of their growth rate and lignifying degree, i. e. Taiwan pine, Masson’ s pine > Japanese red pine, Japanese black pine, which indicated that there was a certain connection between them. When treating the germinating materials with cycloheximide (CHM), their PAL activity increased by several times, which showed that as the same of annual herbaceous crops, the endogenous inhibiting substance for PAL also existed in the germination of gymnosperm during the germination of their seeds.