To provide a block structure suitably usable for a ground reinforcing material buried in the ground for strengthening the weak ground, a slope protection frame arranged on a slope face for protecting the slope face, a block wall, an aggregate embedded in a wall body such as a wall and the other various structures, a grating and a fence arranged in a building for a sun shade, a blindfold, and decoration.

This block structure has a form of vertically and horizontally combining and continuously arranging a square frame body 8 by performing electrofusion by inserting a resin pipe 3 cut in a proper length into upper, lower, left and right attachment ports 2 of an electrofusion joint 5.