Lamellar single crystals of poly(butylene succinate) (PBS) with novel morphologies were prepared from a chloroform/methanol solution by self-seeding methods. Crystal structures and morphologies were investigated by means of atomic force microscopy (AFM). Lath-shaped crystal and hexagonal-shaped crystals coexist in one PBS single crystal and this has a lamellar thickness of around 5-6 nm as determined by AFM. The thickening of lamellae from 5-6 to 7-9 nm occurred during heating from 41 to 84 degrees C. In situ temperature-controlled AFM observations demonstrated that the lath-shaped crystal sections melted first and then the hexagonal sections while the edge of the single crystals remained regular during annealing. (C) 2009 Wiley Periodicals, Inc. J Polym, Sci Part B: Polym Phys 47: 1492-1496, 2009