Abstract: 【Objective】 The effects of different types of chemical capping agents on the agronomy and spatio-temporal distribution of cotton bolls in southern Xinjiang were studied,and the feasibility of chemical capping instead of manual capping was analyzed,with the aim of providing theoretical basis and technical reference for the demonstration and promotion of cotton chemical capping technology.【Method】 In 2020,a field experiment was conducted at the experimental site of the Third Division Agricultural Science Research Institute in Tumushuke City,Xinjiang,using artificial topping as a control and using a completely random design. The effects of Tuyouta agent with flumetreamine and Zifengding agent with cyclophenin as the main component on the cotton agronomic and spatio-temporal distribution of cotton bolls were studied.【Result】 The cotton plants treated with Tuyouta stopped growing at the top after 20～30 days of application,and the top of the cotton plants treated with Zifengding stopped growing after 15～20 days of application,and finally achieved the effect of capping; the total number of bolls was Tuyouta＞Zifengding＞artificial topping,among which,Tuyouta had 1. 74 more than artificial topping,and there was no significant difference between Zifengding and artificial topping,Tuyouta had an increasing effect on autumn boll,and Zifengding had an increasing effect on summer boll,and both pharmaceutical treatments could increase the amount of boll load on the upper part of the cotton plant;Compared with manual topping,the output of Tuyouta increased by 11. 5%,and there was no significant difference between the output of Zifengding and manual topping.【Conclusion】 The capping effect can be achieved by Tuyouta and Zifengding,but the yield enhancement effect of Tuyouta is better than that of Zifengding,and can be used as a suitable agent for chemical capping in the Xiaohaizi Reclamation Area in southern Xinjiang.