Writing instrument gripping aid and writing instrument having the same

A writing instrument gripping aid, comprising a hollow prism body consisting of a thumb positioning face, an index finger positioning face and a middle finger positioning face, which respectively comprise a thumb positioning structure, an index finger positioning structure and a middle finger positioning structure, wherein a cross-section perpendicular to a longitudinal direction of the hollow prism body defines a curvilinear isosceles triangle with both base angles greater than 60 degrees and wherein the index finger positioning structure is lower than the thumb positioning structure.