Electrochemical synthesis of Co-W alloys from citric electrolyte with boric acid additive in current density interval 0,5 – 30 A/dm2 and electrolyte bulk temperature interval 20−56 ºС has been studied. It is shown that increase of electrolyte bulk temperature allows: a) to enlarge the current density interval in which alloy deposition realizes with the maximal current efficiency (~ 70%); b) to ensure considerable decrease of deposit fissuring; c) to increase the tungsten content in alloy; d) to extend the potentialities of alloy morphology and alloy structure control. It is shown that at higher electrolyte bulk temperatures amorphous deposit develops into nanocristalline structure mainly consisting of α−cobalt. Changes of alloy composition and structure with current density increase and increase of metallic component in deposit lead to considerable decrease of current density influence on the surface temperature increment during electrodeposition.