The invention discloses an erythropoietin receptor modified electrode, which is a glassy carbon electrode with erythropoietin receptor as recognition element fixed onto the electrode surface via ZnO sol-gel. The modified electrode can be prepared easily, and its performance is stable. After 50-day storage in the dark at 4° C., its response current remained approximately 77% of the original value. An electrochemical biosensor using this modified electrode as working electrode, a platinum electrode as counter electrode, a saturated calomel electrode as reference electrode, and 2 mmol/L K3[Fe(CN)6]—K4[Fe(CN)6]phosphate buffer as the test base solution, can detect erythropoietin (EPO) and/or recombinant human erythropoietin (rhEPO) in a fast, specific, and sensitive manner, with a linear range of 5 pg/L-500 ng/L and a limit of detection of 0.5 pg/L. In particular, according to peak potential differences, the biosensor allows accurate discrimination of EPO and rhEPO. It may be used not only for detection of low concentrations of EPO or rhEPO, but also for detection of the stimulant rhEPO in sports games.