This study was conducted to investigate sodium and potassium balances, as well as correlations among the relating factors in adult males and females. We collected blood, urine and feces samples as well as a dietary intake survey from 50 subjects. Then, we analyzed the sodium and potassium contents in blood, urine and feces, and evaluated their state of balance. The average ages of the study targets were 24.7 years old for males and 22.8 years old for females. The daily energy intake by the males was 1733.4 kcal and by the females was 1570.3 kcal. Sodium intakes were 138.3 mEq and 127.5 mEq for males and females, respectively. Potassium intakes were 43.1 mEq and 49.3 mEq, respectively. The daily excretions of sodium through urine were 136.6 mEq by males and 97.0 mEq by females and the excretions through feces were 2.2 mEq and 2.0 mEq, respectively. The daily excretions of potassium through urine were 20.2 mEq and 16.5 mEq by males and females respectively, and the excretions through feces were 7.7 mEq and 7.5 mEq male to female. The retention rates of sodium were 11.7% and 14.1% male to female, respectively, and the apparent absorption rates were 98.5% and 97.8%. Additionally, the retention rates of potassium were 32.9% and 39.8% and the apparent absorptions were 81.9% and 81.3%, both male and female. It was noted that, overall, the sodium intake of adult males and females is still higher than the recommended daily sodium intake, while the potassium intakes and excretions were found to be lower. Based on the results of this study, nutritional guidance and education is recommended to encourage decreased sodium intake and increased potassium intake, according to recommended standards.