Abstract: In China Macrobrachium nipponense (De Haan) is an important commercial fresh-water prawn, which is widely distributed in rivers, lakes and ponds. This paper describes the larval development of this prawn under laboratory condition. To complete the entire course of larval (levelopment, some larvae molt only ninetimes, others, however, molt 10, 11 or even 14 times. This report gives description ofthe 9-molting stage larval development, from first stage to ninth stage and postlarva,with detailed illustrations on the morphology of larvae and their appendages. The duration of larval development was governed by water temperature. Under26.5±1.3℃ the larvae accomplish their metamorphosis to the postlarval stage in 21 days,whereas under 30.9±1.2℃, they require only 16 days.