Abstract: In accordance with optimum revamping of structure of mould copper plats for a 1400mm X 170mm slab con- caster, a numerical simulation for 3- dimensional temperature fields of mould copper plats with two kinds of copper plate and immersed nozzle structure parameters before and after revamping has been studied by finite difference control volume method ,The results obtained by simulation showed that the heat transfer effects of copper plate for wide face of mould obviously increased by optimum revamping with bolts gap modified from 160mm to 135mm and cooling water channel number modified from 65 to 55, with costing speed 1.4 m/min, at region nearby meniscus, the waximum temperature of inner and out curved wide face copper plate of mould after revamping respectively decreased by 15 ,^2 and 16 ,^0 as compared with that of mould before revamping.