The deformation properties of two molecular weight poly(ε- caprolactone) (PCL) and its blends with the amorphous polymer PVME or SAN at different ratio under a tensile load have been investigated by means of differential scanning calorimetry (DSC) and in situ synchrotron small-angle X-ray scattering (SAXS). It was found that the long spacing (dac) of the structure increase with the increase of the stretching temperature and content of the amorphous polymer, while the lamellar thickness (dc) remain almost still. Results indicated that the amorphous polymer PVME and SAN was incorporated into the amorphous phase of PCL. And the incorporated chains increase with the increase of amorphous polymer content and stretching temperatures. The long spacing of deformed blend samples (dac) of the structures decreased on account of the phase separation of the blends. In a phase diagram of inverse lamellar thickness and temperature, the crystallization behaviors can be described by linear dependencies of different slopes and different limiting temperatures at infinite crystalline lamellar thickness. The slope of the crystallization line depends on the surface free energy of the just formed native crystallites, which decrease with the with the amorphous polymer content. Such changes are consequences of changes in molecular during crystallization for samples with different amorphous contents.