A moderate halophilic bacterium Yangia sp. ND218 which was isolated from mangrove soil samples in Giao Thuy district, Nam Dinh province, was found to be able to synthesize co-polymers consisting mainly of 3-hydroxybutyrate and 3-hydroxyvalerate from different carbon sources. Batch fermentation for PHA production by Yangia sp. ND218 under unsterile condition with glucose as the carbon source was investigated. The maximum CDW of 5.8 g/L and PHA content of 25.1 percent were obtained under unsterile conditions, higher than those obtained under sterile conditions. The utilization of an unsterile medium for PHA production is a new discovery that could reduce the cost of polymer production.