[Objectives] In order to solve the environmental problems caused by excessive application of chemical fertilizer in Hexi irrigation region, the effects of organic nitrogen replacing part of inorganic nitrogen fertilizer on the growth, yield and quality of wine grape were explored to determine the appropriate amount of organic-inorganic nitrogen fertilizer for wine grape.[Methods] A field experiment was conducted at Linze County, Zhangye City, Gansu Province in 2018. Six treatments were set up:no fertilization input as control (CK), 100% chemical fertilizer (C), 100% organic fertilizer (O), 30%, 50% and 70% of the chemical fertilizer supplied by organic fertilizer, recorded as 0.7 CO, 0.5 CO and 0.3 CO. The effects of different ratios of organic and inorganic fertilizers on the growth, yield and quality of Merlot were studied.[Results] The yield and quality of wine grape could be improved by replacing part of chemical fertilizer with organic fertilizer, and the effect of 0.5 CO was the best. Under the same amount of organic fertilizer, 0.5 CO treatment could balance vegetation growth and reproductive growth. Compared with CK and C treatment, 0.5 CO treatment increased the grape yield, fruit soluble solid content, sugar content, tannin content, total phenol content, anthocyanin content and the ratio of sugar to acid by 120.76% and 32.59%, 46.72% and 25.21%, 39.36% and 37.46%, 23.05% and 39.06%, 72.07% and 54.77%, 44.42% and 48.48%, 50.42% and 40.78% (p<0.05), respectively, and the total acid content was decreased by 33.96% and 16.98% (p<0.05), respectively.[Conclusion] Under the premise of reducing chemical fertilizer, half of chemical fertilizer combined with organic fertilizer (0.5 CO) can not only effectively inhibite the vegetative growth of wine grape, but also improve the yield and fruit quality of wine grape. It is recommended that organic fertilizer (9 000 kg/hm²) combined with N of 150 kg/hm², P₂O₅ 135 kg/hm² and K₂O kg/hm² should be adopted for wine grape cultivation in the study area.