Obesity is a complex metabolic disease, which induces a variety of diseases, such as cardiovascular disease, type 2 diabetes, hypertension, and cancer. Various chemical agents can be used for treat obesity, but adverse some side effects, such cardiovascular disease and stroke. Natural products reported possessing anti-obesity activity. Mytilus edulis (ME) has been associated with some functional properties such as antioxidant and anti-inflammation. This study aims to determine the preventive effects of Mytilus edulis water extract (MWE) on male reproduction dysfunction in high-fat diet (HFD)-induced obesity rats. The Sprague-Dawley (SD) rats used for obesity model and fed by HFD for 13 weeks. The rats were treated with three different doses of MWE (MWE1, 150 mg/kg body weight; MWE2, 300 mg/kg; MWE5, 750 mg/kg). The results showed that the MWE can reduce body weight, total cholesterol (TC), and triglyceride (TG). In reproduction function, MWE showed that the percentage of sperm motility and progressive motility significantly increase compared to no treated-HFD group. MWE was also reduced oxidative stress and increase the enzymatic antioxidant activity such as superoxide dismutase (SOD) and glutathione peroxidase (GPx). In the conclusion suggested that MWE had beneficial effects on the male reproduction dysfunction in HFD-induced obese rats