An optical bi-directional transceiver module is disclosed. The optical bi-directional transceiver module is suitable for an optical transmission/reception operation on the condition that an interval between two wavelength bands such as C and L bands is very narrow. The transceiver module manufactures a stable optical-communication light source based on the injection-mode-locked FP LD, such that an improved light source capable of substituting for the conventional high-quality DFB laser can be implemented. As a result, the light source for the WDM-PON system can be manufactured. The optical bi-directional transceiver module can be manufactured even when the light signal having a narrow interval between two wavelength bands is used, resulting in reduction of costs, size, and power consumption of the light source.