A toy block, configured to be assembled with a mating block, has four sidewalls. The toy block includes, where applicable, at least one stud, at least one recessed portion, bottom posts, semi-circle posts, rib pairs, a plurality of edge stoppers, and a plurality of corner stoppers. The studs and the recessed portion are provided at the top side and at the bottom side of the toy block respectively. When one of the studs of the mating toy block is inserted in one of the recessed portions of the toy block, each one of the engaged studs of the mating toy block has its sidewall abutting against eight abutment points in its corresponding recessed portions of the toy block. Thus, the toy block is grasped with the mating toy block at the engaged studs of the mating toy block.