Abstract: In order to master activities of Carposina niponensis and provide theoretical basis for effective forecast and prevention, the occurrence of Carposina niponensis in orchards were studied by the method of sex attractant trapping. The results showed that Carposina niponensis had 2 or 3 generations per year in orchards, the amount of adult peak occurred in July 20th, with generation overlapping. The distribution of adults had no significant difference at 1.0-2.0 m height of the apple tree. In the application of sex attractant for the adults, according to the principle of easy to operate, sex attractants were randomly arranged at 1.0-2.0 m height of the apple tree, but it did not affect the trapping effect. The adults mainly acted in 22:00 to 6:00 of the next morning, whose activities were the most frequent and active in 0:00 to 2:00. The occurrence of Carposina niponensis in orchards were further understood to provide theoretical basis for more effective treatment.