Abstract: In 1976 to 1978 a series of studies on short-term forecast of the occurring period of Gravitarmata margarotana Hein．Were carried out in Jiansnanpo of Fushun county，Sichuan．The results obtained are shown as in the following：1.When the egg colour changes from orange-red into black，it is apparent that the egg will soon be hatching．2．According to observation，the threshold for development and the effective thermal summations of the eggs are 8.3℃ and 85.9 day degreeres Dectively．The “effective thermal sums”equation and the meteorological report was used to estimate the occurring period of larvae.3．When the female Sex-ratio is changed from 0.3 to 1，the emergence of moths reached their highest peak，which may be observed in the laboratory or with the aid of investigation in the field．4．The occurring period of the larvae and adults with the phenological relationship of the common China fir，peach，apricot and tung-oil tree were also observed．