Abstract: Surface of cuprous chloride was modified by organic coating agents.A quantitative analysis method,i.e.variation relationship between sample purity and time at a specific environment (moisture-laden air),used to characterize the inoxidizability of cuprous chloride was confirmed by experiments.Modification effects of different coating agents were also investigated.In allusion to all the selected coating agents,another study on the influence of amount of coating agent,coating time,and coating temperature on anti-oxidizability of cuprous chloride was carried out.Result showed that surface covering can slow down  oxidation rate of cuprous chloride in the air (humidity is about 70%),and improve its capability of antioxidation at the same time.It also found that citric acid was the best coating agent. EPMA and IR were employed to investigate modification effects and possible modifying mechanism of organic coating agents to cuprous chloride.  