Abstract: In order to investigate the environmental condition of deep litter system of pig housing in winter, the paper was conducted to determine the environmental indicators. The study have determined the temperature, humidity, light, airflow velocity , ammonia content and carbon dioxide content every three days in the pig housing and each measurement was in the morning , afternoon and evening. The results showed that the temperature in it could reached 17.36℃, the humidity was relatively higher, but the environment could basically meet the growth requirements of the pigs. The temperature of the pig litter in deep litter system was 26.14℃ at 10 cm, and the temperature was 26.35℃ at 20 cm. Ammonia concentration of the pig housing was 10.71 mg/m3, and the concentration of carbon dioxide was 0.13%. The contents of ammonia and carbon dioxide were both in the range of hygiene, which would play no adverse role in pig production performance. Under the conditions of this experiment, the feeding pattern could raise the temperature inside the pig housing, improve the environment significantly and resolve the problem of manure pollution effectively.