From the roots of wild Dendrobium thyrsifoorum, six strains of orchid mycorrhizal fungi (Dt1, Dt2, Dt5, Dt6, Dt7, and Dt8) were obtained and inoculated onto the roots of tissue-cultured Dendrobium thyrsiflorum and Dendrobium candidum seedlings The growth of the seedlings inoculated with fungi was compared with that of those not inoculated. The results showed that inoculation improved growth of tissue-cultured Dendrobium seedlings and increased the number of buds and roots. And the effects of fungi Dt5 and Dt8 were better than that of the other fungi. It is of a potential value, that these two fungi are applied to Dendrobium cultivation.