A simple electrochemical biosensor was developed based on graphitic carbon nitride polymers (g-CN) modified glass carbon electrode (g-CN/GCE). The modified electrode displayed the electrochemical sensitive to dopamine (DA) and showed a good linear and broad response to detect of DA. The inorganic ions had no effect on detecting of DA as well. The decreasing of electrochemical activity was only about 10% after exposure in PBS solution for 15 days which showed excellent stability and reproducibility. It is suggested that the g-CN biosensors have promising application for DA analysis.