Provided is a suction pipe assembly with improved heat conductivity and a manufacturing method thereof. The suction pipe assembly includes a suction pipe, a capillary, a heat transmission pipe, and an adhesive agent. The suction pipe is disposed between a compressor and an evaporator and guides a refrigerant ejected from the evaporator to the compressor in a cooling system executing cooling by circulating the refrigerant and including the compressor, the condenser and the evaporator. The capillary is disposed between the condenser and the evaporator and guides the refrigerant ejected from the condenser to the evaporator. The heat transmission pipe includes the capillary inside and a contact portion for widening a contact area to the suction pipe outside to tightly contact the suction pipe. The adhesive agent is interposed between an external surface of the suction pipe and the contact portion to connect the heat transmission pipe with the suction pipe.