Electrochemical　reduction　of　nitrogen　to　ammonia　under　mild　conditions　provides　an　intriguing　approach　for　energy　conversion.　A　grand　challenge　for　electrochemical　nitrogen　reduction　reaction　(NRR)　is　to　design　a　superior　electrocatalyst　to　obtain　high　performance　including　high　catalytic　activity　and　selectivity.　In　the　NRR　process,　the　three　most　important　steps　are　nitrogen　adsorption,　nitrogen　activation,　and　ammonia　desorption.　We　take　MoS2　as　the　research　object　and　obtain　catalysts　with　different　electronic　densities　of　states　through　the　doping　of　Fe　and　V,　respectively.　Using　a　combination　of　experiments　and　theoretical　calculations,　it　is　demonstrated　that　V-doped　MoS2　(MoS2-V)　shows　better　nitrogen　adsorption　and　activation,　while　Fe-doped　MoS2　(MoS2-Fe)　obtains　the　highest　ammonia　yield　in　experiments　(20.11　mu　g　center　dot　h(-1)center　dot　mg(-1)cat.)　due　to　its　easier　desorption　of　ammonia.　Therefore,　an　appropriate　balance　between　nitrogen　adsorption,　nitrogen　activation,　and　ammonia　desorption　should　be　achieved　to　obtain　highly　efficient　NRR　electrocatalysts.