Twenty PHA producer bacteria were isolated and screened from waste water collected from Mach Trang village, Dong Anh district, Hanoi city. Among them, the highest PHA producer bacterium - strain MT33 was chosen for further study. Strain MT33 is a gram-positive and rod-shape bacterium, able to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 3 percent mol HV unit. The optimum conditions for cell growth and PHBV production by strain MT33 are glucose of 20 g/L, yeast extract of 3 g/L, pH 5,5 - 7, and temperature 30 - 32oC. Maximum CDW and PHBV content of 5,08 g/L and 67 percent were respectively obtained by strain MT33 after 36 h of cultivation at optimal condition.