Abstract: Bacillus subtilis,Trichoderma harzianum and streptomycete were selected as test materials.The effects of different treatments on the vegetative growth and fruit quality of muskmelon were studied by measuring the plant height,stem diameter,leaf area,single melon weight,total soluble solids content,soluble sugar and ascorbic acid in pulp,in order to screen the suitable growth-promoting bacteria biostimulants for netted melon.The results showed that 0.1g·m^-2 Trichoderma harzianum at 7 days and 14 days after colonization and 7 days and 25 days after pollination could improve soil microbial environment and root activity of netted melon plants,the contents of soluble solids and total soluble sugar were increased to 15.60%in center and 12.77%in edge of netted melon fruit.