Lahan swamp is the fourth largest national wetland of Thailand. Unfortunately, there are many problems in the swamp, for example, the expansion of residential and industrial areas, alkaline soil from rock salt, decomposition of dead plants especially algae, pesticide and herbicide contamination from agriculture, and biodiversity reduction such as in fish likely due to overfishing and unsustainable fishing methods, the reduction in bird population because of roadway construction, levee construction and fishery, invasive plant species and the extinction of native aquatic plants [2]. Meanwhile, management and monitoring of this area is still limited. Thus this study is aimed at evaluating physical, chemical and biological qualities of Lahan swamp and to give suggestions for future management of this valuable wetland.