Induction air unit was improved by decrease the induction ratio and add the rectifier. Performance test on fan coil unit and improved induction air unit system was carried in the model houses. Test results showed:Induction air unit system could meet the temperature requirement of room. It had a strong dehumidifying ability and much uniformity air velocity in the range of comfortable.Induction air unit system had little temperature gradient and difference.The unit was energy efficient combined with the extensive air handling unit and medium chiller. Improved induction air unit would be used in the high quality air conditioning spaces.