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Free poly(L-lactic acid) (PLLA) sheaves and spherulites were prepared by thermally induced phase separation method from its tetrahydrofuran solution without the assistance of other additives. The effects of variables such as polymer concentration, quenching temperature and time on the morphology of PLLA spherulites were studied. The morphology, size, degree of crystallinity, and crystal structure of spherulites were characterized by SEM, DSC and XRD, and so forth. No obvious sheaves or spherulites were observed at quenching temperature of 8 and 0 C, whereas sheaves composed of fluffy nanofibers with diameter of about 250 nm were formed at quenching temperature range of 210 to 240 C. With increasing quenching time, the PLLA morphology changed from small sheaves to big sheaves (cauliflower-like) to spherulites. Low concentration (3 and 5 wt %) solutions were favorable for the formation of sheaves, whereas high concentration (7 wt %) solution as good for the formation of spherulites. The mechanism for the formation of PLLA sheaves or spherulites was examined by the isothermal and nonisothermal crystalliza-Poly (L-lactic acid) (PLLA) has been widely used in the biomedical field. 7-10 It has many advantages of biocompatibility, hydrophilicity, and controllable degradation for clinical applications. Further, PLLA is a semicrystalline polymer. There are many reports on PLLA spherulites from its melt. For example, Miyata et al. 11 reported the growth characteristics of PLLA spherulites at various cooling rates from 200 C to room temperature. Cho et al. 12 studied several peculiarities of PLLA spherulites prepared at high crystallization temperatures above 130 C. There were a few reports on the PLLA crystallization from solution. Single crystals of PLLA were formed from 0.05 wt % PLLA-g-PCL/hexyl alcohol solution system at 50-80 C. 13 The rhombic and stelliform crystal of PLLA also were formed from 0.08 or 0.01 wt % PLLA/ acetonitrile solution system at 25 C. 14 However, there are few reports on PLLA spherulites from solution at low temperature.Thermally induced phase separation (TIPS) process was widely used to fabricate porous materials. This technique is Additional Supporting Information may be found in the online version of this article.