【目的】评价小反刍兽疫活疫苗在免疫接种后的抗体消长规律。【方法】在新疆生产建设兵团第四师选取2家散养户（A场、B场）采取“一年一免”的免疫方式进行免疫，2家规模养殖场（C场、D场）采用“三年一免”的免疫方式进行免疫，在免疫后30 d开始每隔3个月抽样监测，采用阻断ELISA方法检测抗体水平。【结果】“一年一免”的羊群在免疫后30 d、90 d、180 d、270 d抗体阳性率均达到85%以上；“三年一免”的羊群在免疫后630 d抗体阳性率下降至70%。【结论】小反刍兽疫疫苗在630 d内具备较好的防控作用，建议每隔21个月对羊群进行及时补免，以实现更好的免疫保护成效。

【Objective】This study was aimed to explore the change law of immune antibodies after vaccination with peste des petits ruminants(PPR)live vaccine.【Methods】Two scaled farms and two smallholders in the 4th division of Xinjiang production and construction corps were selected for the immunization experiment,sheep in the former were vaccinated once in three years,and in the latter once per year.Samples were collected every three months since the 30th day after vaccination,and the antibodies were detected using a blocking ELISA method.【Results】The antibody positive rates of the sheep vaccinated once per year all reached more than 85%at 30,90,180 and 270 days after immunization,while those of sheep vaccinated once in three years decreased to 70%at 630 days after immunization.【Conclusion】The prevention and control effect of PPR live vaccine was good within 630 days,and it was recommended that sheep should be given timely supplemental vaccination every 21 months to achieve a better immune protection.