An opening structure of a tool grip includes a left grip and a right grip that are intersected and pivoted. An elastic connecting strap is provided between the left and right grips. The left grip has at least two left studs. The right grip has at least two right studs. The connecting strap has a length greater than a distance between the left and right grips. One end of the connecting strap has at least two left recessed portions for engagement of the left studs. Another end of the connecting strap has at least two right recessed portions for engagement of the right studs. By selecting the position where the left recessed portions are engaged with the left studs and the position where the right recessed portions are engaged with the right studs, a force that the connecting strap pushes against the left and right grips to open is adjustable.