The ammonia volatilizations were studied from red paddy soil under the treatments of controlled-release urea enveloped with colophony (CN) and common urea (UN). The results indicate that: 1) Ammonia volatilization flux of CN treatment decreased by 28.57% in 2 - 4 d in base N phase and by 25.00% in 1 - 2 d in dress N phase; and the peak volatile values occurred at the 5th d in base N phase and the 4th d in dressing N phase, and both were later than UN treatment. 2) Ammonia volatilization flux of CN treatment increased greatly after 2d in the dressing N phase than UN treatment. Therefore, the reasonable pattern of basal CN fertilization should be adopted to get the better environment benefit.