An original physical based modelling predicting flow stress and microstructure evolution during cold rolling for ferrite/pearlite steels has been developed and validated. Using the, chemical composition, the initial ferritic grain size, the initial pearlite interlamellar spacing and the pearlite volume fraction, the model is especially suitable to compute during cold rolling : the macroscopic stress versus macroscopic strain, the local stress-strain state in each phase, the ferrite grain size morphology evolution, the pearlite interlamellar spacing refinement.