This experiment was conducted to determine Gibberellin content in tobacco leaves at different growth stages in relation to nitrogen levels applied. Some of the results obtained can be summarized as follows: 1. The content of Gibberellin showed an increasing tendency as the levels of nitrogen increased. 2. The highest content of Gibberellin was observed at 60 days after transplanting, showing much higher than those of 30 and 90 days after transplanting. 3. The content of Gibberellin at various growth stages under different nitrogen levels ranged from 0.2490 ng to 10.9308 ng per IKg of fresh leaf weight of Burley 21. 4.The kinds of Gibberellin present in tobacco leaf appeared to be Gibberellinl ,9,19 and 20.