Abstract: Background and Objective: The accumulation of heavy metals such as cadmium and lead in mussels is very high compared to that in another marine biota. The mussels are sessile, widely distributed filter-feeding organisms, with the ability to sequester many lipophilic organic compounds, absorb anything in their surroundings. The very low mobility allows heavy metal bioaccumulation to occur and cannot avoid pollutants, which increase over time. This bioaccumulation can be toxic to mussels. This study aimed to evaluate the effect of different toxic chemicals and histological changes in green mussels. Materials and Methods: All archive gonad sample of green mussels in 2015 was fixed in paraformaldehyde 4% solution and were sliced by a rotary microtome at 8 μm thickness and finally, the slides were stained with a solution of hematoxylin-eosin. Results: The obtained results demonstrated that developmental disorders in the testes are characterized by the arrangement of follicle cells in a relatively less dense state and some follicles are not fully filled with spermatozoa. It means that the male gonad samples of green mussels in the port of Muara Angke undergoing toxicity and the process of gonad developmental was disrupted. Conclusion: The effects of toxicity of the male gonad of green mussels were more sensitive and were more susceptible than the female gonad of the green mussels.