The cold crystallization behavior of glassy poly(lactic acid) was studied by comparison among samples obtained through three different treatments, which are naturally cooling (NC), liquid nitrogen quenching (NQ), and rapidly compressing (RC). The crystallization kinetics and structural changes of these glassy samples were analyzed by using in situ Fourier transform infrared (FTIR) and in situ wide angle X-ray diffraction measurements. The results reveal that, the cold crystallization behavior is very similar between NC and NQ samples, but RC sample exhibits higher crystallization rate and lower crystallization temperature than them. FTIR investigation showed that, during the heating process for all the glassy samples, conformational adjustment in the amorphous phase occurs first, and followed by formation of the disordered crystals and then the disordered crystals further perfecting, while for RC sample the onset temperature of each step is much lower. Furthermore, for RC sample, the crystal grain number is larger and its initial form crystal induced by the heating is higher ordered than that of the others, and this unique crystallization behavior might be caused by the local ordered domains formed during the RC process. POLYM. ENG. SCI., 55:359-366, 2015. (c) 2014 Society of Plastics Engineers