There is provided an ultra-thin and high strength three-piece can-making plated steel sheet which is excellent in weldability and flange forming processibility containing C .ltoreq. about 0.004 wt %, Si.ltoreq. about 0.03 wt %, Mn: about 0.05-0.6 wt %, P.ltoreq. about 0.02 wt %, S.ltoreq. about 0.02 wt %, N.ltoreq. about 0.01 wt % Al: about 0.005-0.1 wt %, Nb: about 0.001-0.1 wt % and the balance of inevitable impurities. The steel sheet has a maximum recrystallization grain size of 30 .mu.m or less and a ratio of area of 50% or more which is occupied by recrystallization grains of about 5-25 .mu.m.