In order to explore the effects of a new nitrification inhibitor 3，4-Dimethylpyrazole phosphate(DMPG)on the growth of grapes，field experiments were conducted in this study，two cultivars of Crimson Seedless and Muscat Hamburg were selected in Xichang city and Qinhuangdao city，respectively. This study aimed to evaluate the effects of DMPG on soil nutrients，grape growth character and fruit quality. Results showed that:compared to CK，0.35% DMPG treatment had a significant effect on the ammonium and nitrate nitrogen contents of Crimson Seedless and Muscat Hamburg grapes soils，the NH4+-N content increased by 17.58%～26.06% and the NO^3--N content reduced by 11.72%～27.42%. But the treatment with DMPG had no obvious effect on soil pH，available phosphorus and available potassium in soils. The chlorophyll content，leaf area and blade thickness of Crimson Seedless and Muscat Hamburg grapes were also increased under DMPG treatment. Compared with CK，the average leaf area and blade thickness of Crimson Seedless and Muscat Hamburg grapes increased by 11.32% and 9.85%，and 9.05% and 16.22%，respectively. Meanwhile，the treatment with DMPG increased the vertical and horizontal diameters，100-grain weight and soluble solids content of grape fruits. The vertical and horizontal diameters of Crimson Seedless fruits in Xichang remarkably increased by 7.2%～11.04% and 7.10%～9.82%，respectively，and the average 100-grain weight increased by 29.14%. While the effect of DMPG on Muscat Hamburg grape fruit characters were not significant. Therefore，the application of DMPG in grape planting can regulate soil nitrogen，improve soil fertility，promote the growth of grape plants and improve fruit quality.