Abstract: By employing the first-principles method based on the density functional theory, the formation energies and electronic structures of single and double vacancies in three kinds of graphene-like materials (namely T graphene, HOT graphene and net W carbon monolayer) have been calculated. The results show that, for these three graphene analogues, the formation energy of double vacancy is always lower than that of single vacancy. HOT graphene has the smallest single and double vacancy formation energy. When a single vacancy is formed, the T graphene changes from a metal to a semiconductor, the HOT graphene changes from a semi-metal to a metal, the net W carbon monolayer remains a metal. However, the double vacancy does not change the electronic properties of the systems. In addition, the three systems with single vacancies have weak magnetism and flat bands, and the electronic states at the flat band are mainly contributed by p_x, p_y orbitals or the combination of p_x, p_y orbitals. The differential charge density map shows that the effect of vacancy on the overall charge density is quite local.