Using ?rst-principles calculations within density functional theory, we systematically investigated the structuraland electronic properties of Metal (Me ? Al, Ga, In, Tl, V, Nb, Ta)-doped WS2 monolayers. The impurity statesinduced by Me substitutional doping are closed to the valence band, showing the p-type characteristic of Me-doped WS2 monolayers. Among Me dopants, Nb-doped WS2 monolayer has the lowest formation energy andslightly local distortion. Subsequently, the covalent character of W–S bond in Nb-doped WS2 monolayer increasescompared with pure WS2 monolayer. It is noteworthy that the feature of direct band gap is still presented in (V-Ta)-doped WS2 monolayers, which is very conducive to microelectronic and optoelectronic applications. Therefore, Nb is the appropriate p-type dopant for the WS2 monolayers based on the present work. These ?ndings mayprove to be instrumental in the future design of new p-type conducive WS2 monolayers.