Age-specific survival, age-specific fecundity and population growth statistics of the cotton leafworm, Spodoptera littoralis (Boisd.) were studied in relation to five different constant temperature regimes over the range of 15-35°C with progressive increments of 5°C. The gross reproductive rate (GRR), net reproductive rate (R_o), intrinsic rate of increase (r_m), finite rate of increase (l), mean generation time (T) and population doubling time (DT) were the basic population parameters calculated to assess the influence of constant temperature regimes on the insect.                 The maximum proportion of individuals still alive (l_x) and mean daily age-specific fecundity (m_x) (0.481 and 201.450) were estimated for the insects reared at 25°C.                 The highest values of (r_m) and (l) with the shortest times of (DT) were recorded at 25 and 30°C, indicating a good adaptability of S. littoralis to increase and survive in a moderately high temperatures of (25-30°C).