To investigate the possibility of applying arbuscular mycorrhizal fungi on vegetable seedlings culture, experiments were conducted with cucumber as test crops to study the influence of arbuscular mycorrhizal fungi infection rate and seedling growth. Seeds of cucumber were sown in 4 mixed substrates and inoculated with AM fungi Glomus intraradics, Glomu mosseae, Glomus etunicatum. The four substrates were vermiculite: ceramsite:perlite:vermiculite=4:3:3, (ceramsite:perlite:vermiculite):peat=9:1, (ceramsite:perlite: vermiculite):water retaining agent=9:1, vermiculite:water retaining agent=1:1. Significant differences were observed in some treatments with respect to mycorrhizal colonization rates and seedling growth of cucumber. The results showed the infection rate of AMF were below 10% in mixture of vermiculite and water retaining agent, the others was below 20%. And Other three kinds of substrates treatments was higher than 22.61%, particularly after inoculated with G. intraradics the lowest infection rate was 87%. The highest seedling vigorous index in media(ceramsite:perlite:vermiculite):peat. It was thus clear that (ceramsite:perlite:vermiculite):peat treatments resulted in the most beneficial effects on seedling vigorous index and infection rate of cucumber roots. Therefore it was the ideal substrate for mycorrhizal seedling of cucumber.