Abstract: The sensitivity of Pristine Graphene (PG), Boron-doped graphen (B-doped graphene), Nitrogen-doped graphene (N-doped graphene) and Sluminum-doped graphene (Al-doped graphene) for one atom toward gas molecule CH2O by using Gaussian 09 program which applies the Density Functional Theory (DFT) with (P3LPY) functional and 6-31G basis set. The results show that the adsorptions of CH2O on B-doped graphene (on atom and center ring) are weak physisorption with an adsorption Energy (Ead) ( 0.273) (0.315)center ring ) eV, otherwise ad center ring doped graphene for this atom could be a good sensor for this gas CH2O. For except the adsorption of CH2O on PG, N-doped graphene and Al-doped graphene on the (atom and center ring) are a strong chemisorption in this case, could catalyst or activate, suggesting the possibility of as a metal-free catalyst.