An insulating terminal base of a connector comprising: a body provided with a plural terminal grooves for placing terminals therein, said body also provided with a clamping member circumference for receiving a clamping member therein for combining terminals stably enough; terminals placed in said terminal grooves; a clamping member provided with an opening to produce proper flexibility to open and close, said clamping member also provided with plural curved surfaces to correspond to the number of said terminals; and said terminals positioned in said terminal grooves and clamped by said clamping member inserted in said clamping member circumference with said curved surfaces tightly pressing said terminal surfaces so as to combine said terminals with said body completely and also to prevent said terminals from loosening off or shifting; and wherein said terminal grooves of said body are provided with first grooves, second grooves and position grooves, said first grooves, said second grooves and said position grooves having a length the same or not the same as those of terminal guiding holes formed at one end of said first grooves, said terminal guiding holes formed in a front wall surface of said body so as to guide an exterior male terminal to combine with said terminal in said insulating terminal base, said second grooves having another end being open, said position grooves of said terminal grooves in said body are respectively provided with two small diameter sections (120, 121) and a large diameter section set between said two small diameter sections (120, 121), said small diameter sections (120, 121) located higher than a bottom wall of said terminal groove; said two small diameter sections (120, 121) have the same inner diameter, but the length the same or not the same; and said large diameter section has an inner diameter larger than those of said small diameter sections (120, 121), and the same or larger than that of an inner diameter of said terminal groove, characterized in that said opening of said clamping member has a width smaller than the diameter of said clamping member to enable said clamping member to flexibly open or close properly; said clamping member is provided with an edge hole to correspond to a location of said position edge of said clamping member circumference of said body, so that mutual combination of said edge hole with said position edge of said clamping member circumference of said body can completely combine said body, said terminals and said clamping member. a body provided with a plural terminal grooves for placing terminals therein, said body also provided with a clamping member circumference for receiving a clamping member therein for combining terminals stably enough; terminals placed in said terminal grooves; a clamping member provided with an opening to produce proper flexibility to open and close, said clamping member also provided with plural curved surfaces to correspond to the number of said terminals; and said terminals positioned in said terminal grooves and clamped by said clamping member inserted in said clamping member circumference with said curved surfaces tightly pressing said terminal surfaces so as to combine said terminals with said body completely and also to prevent said terminals from loosening off or shifting; and wherein said terminal grooves of said body are provided with first grooves, second grooves and position grooves, said first grooves, said second grooves and said position grooves having a length the same or not the same as those of terminal guiding holes formed at one end of said first grooves, said terminal guiding holes formed in a front wall surface of said body so as to guide an exterior male terminal to combine with said terminal in said insulating terminal base, said second grooves having another end being open, said position grooves of said terminal grooves in said body are respectively provided with two small diameter sections (120, 121) and a large diameter section set between said two small diameter sections (120, 121), said small diameter sections (120, 121) located higher than a bottom wall of said terminal groove; said two small diameter sections (120, 121) have the same inner diameter, but the length the same or not the same; and said large diameter section has an inner diameter larger than those of said small diameter sections (120, 121), and the same or larger than that of an inner diameter of said terminal groove, characterized in that said opening of said clamping member has a width smaller than the diameter of said clamping member to enable said clamping member to flexibly open or close properly; said clamping member is provided with an edge hole to correspond to a location of said position edge of said clamping member circumference of said body, so that mutual combination of said edge hole with said position edge of said clamping member circumference of said body can completely combine said body, said terminals and said clamping member.