The objectives of this research were to study the effects of culture system and water quality on Lanchester’s freshwater prawn, Macrobrachium lanchesteri, production. This experiment was divided into 2 trials. Experiment 1 was conducted to determine the effect of manure application (0, 30, 60, 90, 120, and 150 kg/rai/week) in prawn production. A CRD (completely randomized design) of 12 treatments with 3 replication each was applied. Experiment 2 was set to examine the effect of prawn densities (50, 100, 150, 200, and 250 prawn/m2) on its production. Each treatment was replicated 3 times. Each trial was run for 60 days at the Faculty of Fisheries Technology and Aquatic Resources, Maejo University. Prawn production caused by different amounts of manure application was significantly different among treatments (P?0.05). Maximum yield was found in treatment applied with 120 kg of manure/rai/week. Higher application of manure tended to increase prawn production. A number and species diversity of plankton increased when higher manure was applied. A better water quality including ammonia, nitrite, nitrate, phosphorus, and dissolved oxygen as well as the number and species diversity of phytoplankton and zooplankton was observed in the pond with 150 kg of manure/rai/week. Moreover, feeding ponds showed higher phytoplankton and zooplankton than non-feeding ponds. In Experiment 2, different stock densities showed a significant difference in prawn production (P?0.05). Higher stocking densities generated higher production and improved profit. A stocking density of 250 prawn/m2 provided the maximum production and profit. In summary, manure application enhances nutrients and plankton in prawn pond leading to higher production and lower cost. Although higher stocking density provided the decreased in individual average weight gain, there was higher benefit in term of higher production and economic achievement.