Laboratory mass rearing of Spodoptera littoralis (Boisd) on two artificial diets (Kidney beans diet and broad beans diet) was carried out for five successive generations in order to compare some of their biological aspects with those reared on fresh castor bean leaves. Results indicated that, The mean weight of the last larval instars, the percentages of larvae pupation, the mean weight of pupae, the percentages of adult emergence and the number of eggs laid by a female moth were higher for the insects reared on artificial diets than those  reared on fresh castor leaves. These difference in the biological aspects were more pronounced at the 5^thgeneration. for the two artificial diets examined, broad bean diet proved to be the preferable diet for rearing S. littoralis.