For study warm rolling process, warm compression experiment of ferrite combined with pearlite colony was conducted using the Gleeble-3500 thermal/mechanical simulator system. The warm deformation was carried out at temperature (500~700°C) and the strain rate (0.001~10/sec). Based on the flow stress data, the key parameter was calculated. The results show that the warm-working process of carbon steel conforms to hyperbolic sine equation. The relationship of and T could be described by parameter Z (temperature compensation of strain rate factor). The value of apparent n (stress index) and Q (deformation activation energy) was calculated, the draught pressure calculated was 1.87×10⁴ t during warm rolling process at 600°C.