A process for molding a bottle container of a pinch-grip type, which is a synthetic resin blow-molded product and which comprises: a body of a bottle container, and a grip comprising: a pair of right and left deep-recessed grip portions disposed back to back with a narrowest portion in between and formed by concaving both side wall portions of the body of the bottle container toward each other, and a rear wall portion disposed at a position rearward from the deep-recessed grip portions, wherein surfaces of deep-recessed grip portions including at least the most recessed walls have roughened concave-convex wall surfaces where there are many small dents, and the process comprises: using a biaxial stretching and blow molding machine having a blow mold comprising a pair of split molds and a bottom mold, and a pair of movable inserts which can move into and draw back from a cavity formed by the blow mold, and is disposed in areas of mold surface used for molding recessions, which are at roughly middle height positions of pair of split molds, characterized in that molding surfaces of the movable inserts are treated to give roughening mold surfaces where there are many small projections, and a step that the movable inserts allow the positions of a preform that are opposed to the movable inserts to be stretched and deformed into the deep-recessed grip portions, by moving forward the movable inserts at an appropriate point of time during a period in which the preform is stretched and blow molded into a bottle container, and a step that roughened concave wall surfaces are formed on the walls of the deep-recessed grip portions by the walls of deep-recessed grip portions being pushed onto the roughened mold-surfaces by a blow pressure, after the movable inserts cease to move forward. a body of a bottle container, and a grip comprising: a pair of right and left deep-recessed grip portions disposed back to back with a narrowest portion in between and formed by concaving both side wall portions of the body of the bottle container toward each other, and a rear wall portion disposed at a position rearward from the deep-recessed grip portions, a pair of right and left deep-recessed grip portions disposed back to back with a narrowest portion in between and formed by concaving both side wall portions of the body of the bottle container toward each other, and a rear wall portion disposed at a position rearward from the deep-recessed grip portions, wherein surfaces of deep-recessed grip portions including at least the most recessed walls have roughened concave-convex wall surfaces where there are many small dents, and the process comprises: using a biaxial stretching and blow molding machine having a blow mold comprising a pair of split molds and a bottom mold, and a pair of movable inserts which can move into and draw back from a cavity formed by the blow mold, and is disposed in areas of mold surface used for molding recessions, which are at roughly middle height positions of pair of split molds, characterized in that molding surfaces of the movable inserts are treated to give roughening mold surfaces where there are many small projections, and a step that the movable inserts allow the positions of a preform that are opposed to the movable inserts to be stretched and deformed into the deep-recessed grip portions, by moving forward the movable inserts at an appropriate point of time during a period in which the preform is stretched and blow molded into a bottle container, and using a biaxial stretching and blow molding machine having a blow mold comprising a pair of split molds and a bottom mold, and a pair of movable inserts which can move into and draw back from a cavity formed by the blow mold, and is disposed in areas of mold surface used for molding recessions, which are at roughly middle height positions of pair of split molds, characterized in that molding surfaces of the movable inserts are treated to give roughening mold surfaces where there are many small projections, and a step that the movable inserts allow the positions of a preform that are opposed to the movable inserts to be stretched and deformed into the deep-recessed grip portions, by moving forward the movable inserts at an appropriate point of time during a period in which the preform is stretched and blow molded into a bottle container, and a step that roughened concave wall surfaces are formed on the walls of the deep-recessed grip portions by the walls of deep-recessed grip portions being pushed onto the roughened mold-surfaces by a blow pressure, after the movable inserts cease to move forward.