The biochemical components such as total protein, carbohydrate and lipids were measured during larval development of the mangrove crab Metaplax elegans from first zoea to first crab stage. Protein content per larva increased from first zoea, but decreased in megalopa, again increased in first crab stage. Carbohydrate content increased from first zoea to third zoea decreased in fourth and fifth stage and increased in megalopa and first crab stage. The total lipid shows upward trend from first zoe to first crab.