In this study,we practiced plant growth experiment by some chitosans soil mixture treatment in order to examine growth promotion difference in Eustoma grandiflorum (Raf.)Shinn. by using some chitosans ; Koyo chitosan FM-80, FH-80 and FL-80. We recognized that FM-80 and FL-80 chitosan for plant growth showed good effects, compared to SIGMA chitosan. In soil microorganisms, the number of actinomyces increased in chitosan treatment, while the number of Fusarium spp. and filamentous fungus decreased.