This paper presents a study on the coverage of PtAg layer on h-BN 2D system using plane-wave pseudopotential method within density functional theory. There emerge interesting electronic and magnetic properties by the coverage of PtAg on h-BN. FM (ferromagnetic) and AFM (antiferromagnetic) states are considered for PtAg. As the most stable configuration, Pt atom is bound to the top site of N and Ag is adsorbed to hollow site in the (2 x 2) coverage with a binding energy about -1.013 eV. While bare h-BN is nonmagnetic semiconductor with a band gap of 4.58 eV, the band gap becomes 0.18 eV with an AFM semiconductor ground state upon coverage of PtAg adlayer. The electronic structure calculations reveal that the electronic band gap of the composite system is controlled by d-states of Pt atom. The material can have possible applications in spintronics and in catalysis with decreased and engineered band gap. (C) 2014 Elsevier B. V. All rights reserved.