A weldless-type injection mold apparatus is provided. The weldless-type injection mold apparatus includes an upper mold, a lower mold engaged to the upper mold to form a cavity for injection-molding of products, a heating unit formed on one side of the cavity of at least one of the lower and upper molds to heat a resin injected into the cavity, a first cooling unit formed at the at least one of the lower and upper molds to prevent the injection mold from being over-heated, and a second cooling unit installed between the heating unit to cool an area surrounding the cavity and an injection-molded product.