Biological studies of Oryctes rhinoceros L.were carried out under laboratory conditions (20±5C & 55±5%R.H.). Obtained results could be summarized as follows. 1-Egg stage: The incubation period was 13.32 days, while hatchability percentage was 90 %.However, the area of freshly deposited eggs was 7.043 mu2 and increased to 34.26 mu2.before hatching. 2- Larval stage: The durations of first and second larval instar were 22.8, 21.1 days respectively, while that of the third larval instar was 132.1 days. The total larval durations was 176 days .The larval mortalities varied which according to larval instar, they were 22.22%, 18.6%, 14% resp. It was more reduced in the third larval inster under room temperature and total larval mortality percentage was 54.82 %. 3-Pupal stage: The pre-pupal and pupal durations were 15, 21.4 days respectively, while mortality percentages were 22.45 %, 13.16 %. 4-Total developmental periods and total mortality: the Total developmental periods were 225.72 days while the total mortality percentages were 67% respectively. 5- Survival rate of different stages derived from egg: were studied and the results cleared that survival rate was decreased by increasing age were 70 %,57%,49% for larval and 38 % and 33 % for pre-pupae and pupae. 6- Adult stage: adult longevity was 13 days for male while it was 34.4 days for female, pre-oviposition period 6.2 days, 15, 21.4 days oviposition period 10.9 days post- oviposition period 17.3days, fecundity 16.9 egg / female, fertility 72.12 %, life cycle was 231.92 days, total period of generation for male and female were 238.72 & 260.12 days resp.This insect has one generation o\per year.