The electronic structures and magnetic properties of diverse transition metal (TM =Fe,Co,and Ni) and nitrogen (N) co-doped monolayer MoS2 are investigated by using density functional theory.The results show that the intrinsic MoS2 does not have magnetism initially,but doped with TM (TM =Fe,Co,and Ni) the MoS2 possesses an obvious magnetism distinctly.The magnetic moment mainly comes from unpaired Mo∶4d orbitals and the d orbitals of the dopants,as well as the S∶3p states.However,the doping system exhibits certain half-metallic properties,so we select N atoms in the V family as a dopant to adjust its half-metal characteristics.The results show that the (Fe,N) co-doped MoS2 can be a satisfactory material for applications in spintronic devices.On this basis,the most stable geometry of the (2Fe-N) co-doped MoS2 system is determined by considering the different configurations of the positions of the two Fe atoms.It is found that the ferromagnetic mechanism of the (2Fe-N) co-doped MoS2 system is caused by the bond spin polarization mechanism of the Fe-Mo-Fe coupling chain.Our results verify that the (Fe,N) co-doped single-layer MoS2 has the conditions required to become a dilute magnetic semiconductor.