The investigation was carried out to explore the effects of microbial fertilizers on the greenhouse soil microorganism and enzyme activities using the soil of greenhouse Hami melon as test materials,seven treatments were set up,which were EM with three different application methods,three other microbial fertilizers,and CK.The soil was sampled to analyze microorganism quantities and enzyme activities periodically.The result showed that in the same growing period of Hami melon,the soil bacteria and actinomycetes amounts of treatments were all more than CK;The amount of bacteria,actinomycetes were firstly increased and then decreased in the whole growth period;The number of fungi in harvest period were substantially increased than those of the seeding and fruit enlargement stage,especially in CK,which was greatest increased;The urease activity declined,and the invertase activity was firstly decreased and then increased.It was concluded that all the tested microbial fertilizers could improve soil microbial structure,promote the multiplication of bacteria and actinomycetes,inhibit the growth of the fungi;And increase soil urease,invertase and peroxidase activities.Especially,the treatments of “foliar spraying + root irrigating with EM” and “irrigating with N,P,K‘A50’” had obvious effects.