The diseases due to E. coli and P. multocida in ducks have caused economic losses significantly to ducks industry, particularly in the areas of Mekong Delta, in where a large number of ducks is being raised. It is therefore that having a bivalent vaccine made of the local strains are required to be used for preventing against the disease caused by Ecoli and P.multocida in ducks. The results indicated that all batches of the inactivated -bivalent vaccine containing E. coli serotype 078 strain GV13 and P. multocida serotype A:1, strain TG were passed all laboratory tests of sterility, safety and potency. The efficacy of vaccine was also evaluated in the field. The ducks at the times of 1 and 3 months after vaccination were challenged with the virulent strains of E. coli and P. multocida and the results showed that a high rate of 80-100 percent vaccinated duck was protected.