Six bands of domestic and American mayonnaises, four brands of Japanese mayonnaise and one home made mayonnaise were analyzed for chemical and fatty acid and sterol compositions. The results obtained as follows; 1. Moisture content was observed $13.3{sim}22.4%$ of total samples, but H and L samples of American mayonnaise was observed 54.4 and 62.3% for the purpose of low caloried products. 2. Linoleic and linolenic acid were 50.3 and 7.9% and P/S ratio was observed $3.50{sim}4.32$ over ideal ratio. 3. Cholesterol contents in O and N samples of Japanese mayonnaise were 166.07 mg/100 g product, 155.89 mg/100 g product. These figures are 3 times of domestic samples, and 4.8 times of American samples. Cholesterol content in home made mayonnaise was 90.75 mg/100 g product. 4. Little variation in stigmasterol content was observed among the brands of mayonnaise in contrast there was wide variation in sitosterol content ranged from 38.37 mg/100 g product to 409.16 mg/100 g product.