Abstract: The composition segregation of 10 NiCrCu steel produced by continuous casting was characterized through orginal position statistic distribution analysis test, and its microstructure was observed by metallographic microscope. The properties in thickness direction of 10 NiCrCu steel produced by continuous casting were investigated through tensile and tear test. The results showed that alloy elements distributed in positive segregation at the centre of steel thickness, and it made pearlite at the centre of steel thickness was more than that of the surface. Of all the elements, the segregation degree of C, P and S were great, the others were minor. The influence of composition segregation on the strength in thickness direction was slight, but its influence on the plasticity was great. The plasticity in thickness direction declined about 15.5% totally, in which the plasticity at the centre of steel thickness declined mostly due to composition segregation.