Abstract: The paper studied the growth and development of sexual characters, primary sexual maturity, sexual maturity of pond-reared Penaeus monodon in relation to culture conditions in several years. The results showed that the carapace length was positively and linearly correlated to the pudendum length and thelycum width of pond-reared P. monodon. The minimal average carapace length, body length and body weight at primary sexual maturity of pond-reared males and females were 3.1 cm, 11.1 cm,20.0 g and 4.3 cm, 15.1 cm, 53.0 g, respectively. There were not different among different culture conditions. The average carapace length, body length and body weight at sexual maturity of pond-reared males and females were 3.7 cm, 13.0 cm, 37.0 g and 5.0 cm, 17.0 cm, 75.0 g, respectively. The sexual maturity was positively and linearly correlated to day age of pond-reared Penaeus monodon. The culture conditions (density, natural food) were key factors known to influence the growth, development and sexual maturity of pond-reared Penaeus monodon. The earliest time of spermatophore production of the tide pond males (120 days) was significantly earlier (P < 0.001) than the earthen pond males (150 days). The day ages of sexual maturity of male were 160 days (tidal pond) and 260 days (earthen pond), respectively. Prawns started mating at 165 days from tidal pond and at 240-280 days from earthen pond, reached full ovarian maturation and spawned as early as about 205-236 days (tidal pond) and 295-360 days (earthen pond).