Objective To evaluate the stability of Haemophilus influenza type b (Hib)conjugate vaccine stored at 2-8°C.Methods A total of 11 batches of Hib conjugate vaccine put on the market after lot release, manufactured by Yuxi Walvax Biotechnol. Co. , Ltd., were stored at 2-8°C, from which samples were taken at months 0, 3, 6, 9, 12, 18, 24 and 30 after storage for identity test, inspection on final containers, determinations of polysaccharide content, pH value, sodium chloride content, high mol. conjugate content and polysaccharide mol. size, potency test, sterility test, pyrogen test, abnormal toxicity test and bacterial endotoxin test to evaluate the stability.Results All the indexes of Hib conjugate vaccine met the quality standard 30 mo after storage at 2-8°C.Conclusion Hib conjugate vaccine showed high stability after storage at 2-8°C for 30 mo.