The precipitation fluctuation in convective clouds was further observed by radar in June 1984. Through the maximum entro Py method the radar data are analysed, showing that precipitation in warm convective clouds has 0nly one fluctuation in the period of about 20 minutes while that in the cold convective clouds comprises two oscillations with the bigger one in a 20-30 minute period and the smaller in an 11-15 period. The conclusions given in this, paper need more observational data to support.