Ammonia (NH3) and other air pollution emissions from concentrated animal fee ding operations (CAFOs) are becoming more and more serious with the rapid develo pment of livestock and poultry production in recent years. The ammonia emission factor is one of the effective methods for estimating ammonia emissions from CAF Os and evaluating of emission reduction technologies. A continual monitoring sys tem of the NH3 concentration and environmental parameters is used in this rese arch, and the ammonia emission factors and impact factors of the three types of floor systems in the pig buildings are studied. Mean daily emissions per pig fat tened on the semislatted floor system, concrete floor system, and deeplitter system are (947±709), (1123±423), (427±209)g/(d?pig), respectively.