The present work aimed to studying the effect of ethanol extract of Ricinus commnuis L. seeds on biological and physiological for cotton leafworm Spodoptera littoralis 2^nd and 4^th instar larvae. The results cleared that the larval duration were 17.08 &15.58 days and 10.11 & 9.36 days for treated and untreated  of the 2^nd & 4^th instar larvae, respectively. The pupation percent was 60.0 and 96.0 % for treated and untreated of the 2^nd instar larvae and 61.0 and 93.0 for treated and untreated of the 4^th instar larvae. The pupal weight was affected by the botanical extract. The pupal duration was 11.40 and 11.71 days for treated and untreated of the 2^nd instar larvae and it was 11.96 and 12.51 days for treated and untreated of the 4^th instar larvae. The emergence % was 82.0 compare to 97.0 % and 86.0 compare to 98.0 % for the 2^nd & 4^th instar larvae, respectively. On the other hand, the malformed adult was 28.0 and 2.0 % for the 2^nd instar larvae (treated and untreated) and 16.0 & 5.0 % for 4^th instar larvae (treated and untreated), respectively. There are decreasing in fecundity for treatment by botanical extract to S. littoralis 2^nd and 4^th instar larvae. Effect of LC₅₀ value of the tested plant extract on the biochemical aspects of the 4^th larval instar of S. littoralis was detected. The biochemical aspects AST, ALT, alkaline and acid phosphatase and total protein activities post treatment were considered throughout the present study.