By X-ray method was investigated distribution of residual stresses in surface layer carbon steels after ms-pulse laser treatment. The total residual stresses were presented as a sum a) of residual plastic deformations after local thermal influence; b) of bulk effect of structural and phase transformations and c) of processes of saturation of the smelt surface by introduction atoms. With the help of analysis of the structural factors (the dislocations density, the crystal parameter) and mechanical properties were investigated changes of separate components of residual stresses. For steels with 0.08, 0.35 and 0.85 wt.% C was established the correlation between laser treatment modes and character of residual stresses.