The most frequent symptoms among the manifestations of cow milk allergy (CMA) are gastrointestinal. CMA pathogenesis involves immunological mechanisms with participation of immunocompetent cells, production of immunoglobulin E (IgE) and immunoglobulin G (IgG). We aim to determine whether cow milk-specific IgE antibodies coexist with cow milk-specific IgG antibodies in CMA patients with diarrhea symptom, and if there is any relationship between both antibody types. 65 CMA patients (average age of 17years, ranging from 2 to 74years), all of who had diarrhea symptom of CMA, were enrolled in this study. The total cow IgE and IgG subclass in serum were measured by electrochemiluminescence immunoassay and rate immune scatter turbidimetry, respectively. And also the cow milk-specific IgE was determined by enzyme-linked immunosorbent assay. The number of eosinophils in serum was calculated by Sysmex XE-2100 Hematology Analyzer. Our data showed that both cow milk-specific IgG and IgE levels were significantly elevated in CMA patients compared to those of age-matched control subjects. Out of the 65 CMA patients, 40 showed elevated cow milk-specific IgE antibody level, among which, 28 cases presented highly sensitive reaction to cow milk-specific IgG, along with each six of moderate and mild sensitive reaction to cow milk-specific IgG; while 20 showed elevated total IgG levels. The IgG3 positive rate was 16.9%, which was the highest. A moderate correlation between cow milk-specific IgE and cow milk-specific IgG was found in the CMA patients (r=0.415, P=0.001). The results indicated that cow milk-specific IgE antibodies could coexist with cow milk-specific IgG antibodies in patients suffering from CMA. The aberrant changes in the concentration of cow milk-specific IgE antibodies were associated with cow milk-specific IgG antibodies.