Abstract: Effects of nitrogen fertilization on yield and quality of Oolong tea were studied at 6 application levels (i.e., CK, 25% Opt N, 60% Opt N, 100% Opt N, 120% Opt N, and 150% Opt N). The results indicated that, at nitrogen application less than 120% Opt N, the bud density, yield, forest floor, trim amount and biological yield all increased with increasing N. However, when the application was up to 150% Opt N, the effects became either insignificant or negative. The sensory evaluation indicated that the tea quality decreased with increasing N application, although the differences between the treatments were not significant.