The pot experiment was conducted to compare and analyze the changes of the physiological and photosynthetic characteristics of 2 year old Malus hupehensis (Pamp.) Rehd. seedlings of different pretreatments by three consecutive days spraying fulvic acid(FA), glyeine betaine(GB) and combination of fulvic acid and glyeine betaine (FA+GB) and with water as control (CK) pretreatment before drought treatment to explore the physiological drought mechanism of FA and GB for M. hupehensis. The results showed that: (1) compared with the control, FA, GB and FA+GB pretreatment can significantly improve the relative water content in leaves of M. hupehensis, and the water retaining effect of FA was the best. (2) Under drought stress, the three pretreatments could significantly increase the contents of soluble protein, soluble sugar and proline; and the soluble sugar and proline accumulation of the FA+GB were significantly higher than that of the single application of fulvic acid and betaine treatment. (3) Under drought stress, all the three pretreatments could significantly increase the SOD, POD and CAT activities of seedlings and significantly reduce the accumulation rate and content of MDA. While the pretreatment of FA+GB had the lowest MDA content and the highest antioxidant enzyme activity. (4) The net photosynthetic rate and instantaneous water use efficiency of M. hupehensis treated with GB and FA+GB pretreatments were significantly higher than those of CK and FA. And the photosynthetic characteristics of FA+GB were the best, followed by GB. The results showed that under the drought stress, spraying fulvic acid, glyeine betaine and combination of fulvic acid and glyeine betaine on M. hupehensis leaves could increase the osmotic adjustment substance, the waterholding capacity and the relative water content, regulate the activities of antioxidant enzymes, reduce malondialdehyde content, increase cell membrane stability, and could also improve the photosynthetic performance; thereby enhance the drought resistance of M. hupehensis, and effect of pretreatment with compound spraying (FA+GB). Was the best Pamp.