In recent years the number of cabbage worm Pieris rapae has increased in Beni Suef Governorate, and they have threatened the vegetative growth of cabbage crop, especially in the newly reclaimed areas. That study was conducted during the 2017/18 – 2018/19 seasons respectively. Results obtained revealed that there are two distinct peaks for each eggs, larvae and pupae stages per year on cabbage plants. The immature stages covered the entire period of sampling from August 2017, till April 2018 on the cabbage plant. The first peak of egg Population was recorded on November 6 2017 and another smaller peak on mid of March 2018. The maximum larval Population (770 larvae) appeared on November 13, 2017 another smaller peak (450 larvae) on beginning April 2018. Pupal population exerted two periods of abundance On the 22 November, 2017 the highest numbers of pupae were recorded and another smaller peak on mid-April 2018. We can point out that the first and second peak of these stages in 2018/19 came about one to two weeks after the previous season 2017/18. The results also showed that there were statistically significant differences between the number of immature stages and the seasons of the year in cabbage fields. The cabbage sown in autumn season was severely attacked by this pest, followed by spring season. Autumn insect population was about 2-3 folds of winter population. Knowledge of the seasonal abundance of the immature stages is of great valuable to help in planning a control program against this target pest.