Fast scanning chip calorimetry (FSC) experiments are reviewed in terms of the melting of semi-crystalline polymers examined over a wide range of heating rates. The analysis method of melting kinetics is summarized and it is shown that the heating rate dependence of melting temperatures revealed that there are two crystal populations with distinct melting kinetics for isothermally crystallized PA6 and PEEK. Some semi-crystalline polymers showed the following relation between the melting peak temperature, T_m, and the crystallization temperature, T_iso; T_m = T_iso + δT with a constant δT. Quantitative consideration of this issue is discussed on the basis of the Lauritzen-Hoffman standard model of polymer crystallization. We also discuss a method for obtaining the lamellar thickness distribution (LTD) of linear PE by using FSC.