Abstract:The aim of this study was to investigate the content of IgA,IgM and lactoferrin,and their variation affected by somatic cell count (SCC) in milk.Milk from dairy farms in Beijing,Chuzhou,Harbin,Hohhot,Urumqi,Xi’an was collected in spring and summer.The content of IgA,IgM and lactoferrin and SCC in milk were determined.Data was processed by SAS 8.0 and descriptive statistics,correlation analysis,and variance analysis (effects of season and dairy farm on IgA,IgM and lactoferrin) were carried out.The results showed that the content of IgA,IgM and lactoferrin in milk obeyed lognormal distribution.Significant differences of IgA,IgM and lactoferrin content and SCC in milk from different farms were found.The IgM and lactoferrin content from samples collected in spring and summer differed remarkably,but the IgA and SCC data was similar.Correlation coefficients between IgA,IgM,lactoferrin content and somatic cell score (SCS) were significantly positive.Content (log) of IgA,IgM,lactoferrin in milk raised with the increasing of SCS.It can be concluded that significant positive correlation existed between IgA,IgM,lactoferrin content and SCC,and content of IgM and lactoferrin in milk were affected by season.