This study was conducted to investigate the effect of different concentrations of microbial products on growth of chinese cabbage and microorganisms in soil. Two different levels of microbial products, such as 50 times and 100 times diluted solutions of chitosan, wood vinegar and EM activity liquid, were treated for foliar application. The results were summarized as follows : Among foliar applications of microbial products, 100 times diluted solution of chitosan was effective on growth of chinese cabbage comparing to other levels of dilutions and untreated control plot. The number of microorganism in the soil tended to increase under the treatment of microbial products compared to control plot. Especially, the numbers of the bacteria and actinomycetes were estimated 73.67×10³ CFU/g and 34.00×10³ CFU/g, respectively, under the treatment of 100 times diluted solution of chitosan.