To understand the effect of plant growth retardants on the growth of walnut branches and leaves and fruit quality,with 7-year-old Xinxin 2 walnut tree as the experimental material and water as the control,using 200,300,400,500 mg/L of DPC and 500,1 000,2 000,3 000 mg/L of PP₃₃₃,two inductions were carried out during the fruit swelling period and fruit core-hardening period.The length and thickness of walnut twigs and vegetative twigs and fruit quality were measured.And the blade dissect structure was observed.The effects of different growth retardants on the growth,leaf structure and fruit quality of walnut were analyzed.The results showed that the total length of fertile branch,the total thickness of fertile branch and the total length of foliage branch could be reduced by the application of DPC and PP333 ,but DPC had no significant effect on the total thickness of foliage branch. PP333 of 2 000 mg/L could reduce the palisade spongy and the palisade tissue/ mesophyll,and the tannin content was significantly lower than that of the control group. The comprehensive quality of walnut nuts was the best under the treatment of 200 mg/L DPC and 500 mg/L PP₃₃₃.The contents of soluble sugar and tannin in fruits treated with 200 mg/L DPC were increased by 5.3% and 18.2%,respectively,compared with the control group.The contents of soluble sugar and reducing sugar in walnut fruits were increased by 15.8% and 12.0% respectively under the treatment of 500 mg/L PP₃₃₃ compared with the control.The control tip of walnut fruit was the best when spraying DPC or PP₃₃₃ droplet at the expansion stage,and the comprehensive quality of walnut fruit was the best when spraying DPC or PP₃₃₃ droplet at the concentration of 200 mg/L or 500 mg/L,respectively,which could be used for the control tip of Xinxin2 tree.