Abstract: A building block includes a block body of an integrated structure. The block body includes a main body, first splicing portions, second splicing portions, a first raised portion, and two second raised portions. The main body is elongated and horizontally extends from left to right. The first splicing portions horizontally extend outwards from one end of the main body. The second splicing portions obliquely extend forward or backward from a middle position of an upper surface of the main body. An outer side surface of the first raised portion recesses to form first splicing grooves tightly docked with and fixed with first splicing portions or second splicing portions of another building block. Two ends of an upper surface of the main body extend upwards to form the two second raised portions. An upper surface of each of the second raised portions recesses to form second splicing grooves.