Plug-in building block

The utility model relates to an intercalation building block comprising a connector building block provided with a plug, a cylindrical building block, and a plate building block, the two ends of the cylindrical building block are arranged with jacks engaged with the plugs, the side face thereof is provided with a slot of the plate building block. The utility model has the straight figure, rich colors pattern, which is favorable to intelligence cultivation of the children. The building bock takes intercalation connection, and the built figure is firm and hard to be hit down, meanwhile, this kind of connection with the jack connection or the plug connection, which not only can be selected as the best connecting way according to the different shapes of the building block, but also can be convenient for children learning different connecting structure, thereby increasing the knowledge.