The purpose of this study was to develop a functional senior mixed soymilk for seniors and to provide functional senior-mixed soymilk to prevent disease outbreaks. The isoflavone content of senior soymilk was 0.15±0.01 mg/g. The β-glucan content of senior soymilk was 9.82±0.01 mg/g. The weight gain of mice were significantly higher in the high-fat diet group than in the other groups. The serum triglyceride content was high at 102.67±40.61 mg/dL in the high-fat diet group, but significantly lower at 83.00±42.43 mg/dL in the 20% senior soymilk group. Thus, the results of this study comprehensively suggest that food intake should be ingested for each life cycle with reference to the dietary reference intakes for Koreans. In particular, the elderly in their 50s and older are deficient in protein and weakened immune capacity, so it is imperative that they maintain their health through various foods such as soymilk, which is evenly nutritious.