In this study, Rosa roxburghii ‘Guinong 5’ of threeyearold were used as the materials in 2017. Before the flowering period in early May of the same year, the experimental trees were treated with manual priming leaves which rated of 20%, 40%, 60% and 80% of the spring shoots of the same year, and the plants without priming leaves were used as control (CK). The effects of different leaf loss rate treatments on shoot growth, leaf nutrient content, fruit yield and quality of R. roxburghii in 3 years after leaf loss were studied. The contents of endogenous hormones in the spring shoots, the net photosynthetic rate (P_n) and transpiration rate (T_r) of the remaining leaves within 30 days after priming leaf loss, the key enzymes affecting Vitamin C synthesis and accumulation (GalLDH, MDHAR, DHAR, AAO and APX), and key enzymes affecting flavonoid synthesis and accumulation (PAL, C4H, 4CL and CHS) of R. roxburghii fruit in the year were measured. The purposes are to explore the influencemechanism of leaf loss on the growth, fruit yield, quality and related physiological characteristics of R. roxburghii Tratt and to provide a theory basis for the determination of reasonable leaves collection amount and the assessment of the loss of leaves due to disaster of R. roxburghii. The results showed that: (1) the loss of R. roxburghii leaves in spring could promote the germination of summer shoots of the same year, increase the number of summer shoots, and inhibit the growth of new shoots in autumn of the same year, following year and the third year. (2) Within 30 days after priming leaf loss, the contents of IAA and ABA of spring shoot decreased rapidly, while the contents of GA₁₊₃ and ZR increased rapidly. The changes of endogenous hormone had a synergistic promoting effect on the germination of the summer shoots in the same year. The remaining leaves of the spring shoots had an obvious shortterm photosynthetic enhancement compensation reaction. (3) The P_n of the remaining leaves of the spring shoots increased rapidly within 15 days after priming leaf loss, then decreased rapidly, and the photosynthetic compensation reaction could not be sustained in the long term. (4) After the leaf loss rate more than 20% in spring shoots would lead to the nutrient loss of R. roxburghii, especially the loss of N, P, K and Mg elements in the leaves were serious, which inhibited the tree potential and the growth of new shoots. (5) In the critical period of the synthesis and accumulation of Vitamin C and flavonoids in R. roxburghii fruits, the activities of GalLDH, PAL, C4H, 4CL and CHS in fruits were significantly decreased with the increase of the leaf loss rate, and the contents of Vitamin C and flavonoids in fruits also decreased significantly with the increase of the leaf loss rate. In this study, it was found that excessive the leaf loss rate significantly reduced the nutrients contents of leaves and fruit yield and quality, and this adverse effect could last for many years. For R. roxburghii with both fruits and leaves used, the amount of young leaves collection should be controlled within 20% in spring.