Abstract: To investigate ammonia and greenhouse gas concentration condition in swine barn,a hoop structure barn as experiment barn and typical swine barn with brickconcrete floor as control were chose at a confined swine farm in Beijing,gases concentration were measured for 3 consecutive days during spring and summer seasons using INNOVA 1312 multigas monitor. The results showed that the average NH₃、CO ₂、  N ₂ O concentration in experiment barn was by 40%,70%,77%,respectively,compared with control barn (P＜0.05).The average  CH₄  concentration in hoop structure was higher than that in the control barn in summer,but lower in spring.The concentrations of CH₄、CO ₂、  N ₂ O had significant different(P＜005) between summer and spring season in the hoop structure,but NH₃ had no significant different,the CO ₂ concentration was lower in summer,NH₃、CH ₄、  N ₂ Oconcentration was higher in summer than that in spring. The hoop structure barn could improve indoor environment and mitigate gases emission.