This study aims to compare the different effects of moderate-intensity exercise on serum serotonin levels in obese women aged 20-24 years with aerobic, resistance, and combination types of exercise intervention. This research is a field experimental with a pre-test post-test control group design to see an increase in serum serotonin levels. The intervention will be carried out chronically for four weeks. A total of 24 women who met the inclusion criteria were divided into four groups, namely control, aerobic, resistance, and combination groups and tested with moderate intensity exercise. Blood tests were taken before and after the exercise intervention were given to measure the changes in serum serotonin levels. The samples acquired were examined by SPSS version 16. The results of aerobic (2067.59±83.53 ng/mL to 2335.89±77.32 ng/mL), resistance (2067.59±123.99 ng/mL to 2513.57±173.04 ng/mL), and combination (2066.40±104.34 ng/mL to 2725.77±67.16 ng/ mL) exercise for four weeks with moderate intensity showed that the three groups experienced an increase in serum serotonin levels after the intervention. These results concludes the three types of exercise, especially combination of aerobic and resistance exercises, may be used as an alternative indirect therapy method and prevention of obesity.