Abstract:In order to explore the effects of Piriformospora indica on seed germination and protocorm growth of Dendrobium officinale, the morphological and physiological characteristics were studied inoculated by P. indica on seeds and protocorm. The results showed that the initial germination time of D. officinale seeds inoculated with P. indica was earlier than the control, and the height, fresh weight, dry weight, number of leaves, leaf length, leaf width, root number and root length of protocorm of D. officinale inoculated with P. indica were higher than the control. The seed germination rate was 68.8% after 60 days of inoculation, which was higher than the control (28.6%). The chlorophyll a content, chlorophyll b content and total chlorophyll content in the protocorm of D. officinale inoculated for 80 days were significantly higher than the control, chlorophyll a/b was lower than the control, the net photosynthesis rate, stomatal conductance and transpirationrate were higher than the control, and the content of medicinal polysaccharide was significantly higher than the control. Therefore, the seed germination and protocorm growth of D. officinale were promoted by inoculation, and the quality and yield were improved.