Abstract: Methods to evaluate the level of free-cementite, pearlite in low carbon deformation steel, banded structure and Widmanstatten structure in low carbon or medium carbon steel plate, strip and section bar, were prescribed in GB/T 13299-1991 “Steel-Determination of Microstructure”. In the past 20 years of practical application, the standard exposed a lot of problems in aspects of application scope, sampling and test surface, carbon content boundaries and evaluation of the level of pearlite and banded structure in low carbon deformation steel. These problems were analyzed and discussed, and some suggestion was proposed to perfect the standard.