The crystallization behavior of PBA on highly oriented PE substrate from solution as well as melt was studied by optical microscopy, transmission electron microscopy, and X-ray diffraction. The results show that the PE exhibits very strong nucleation ability toward PBA as reflected by the occurrence of heteroepitaxy and transcrystallization of PBA on the PE substrate. The epitaxial crystallization of PBA on PE substrate results in the formation of beta-PBA crystals at any crystallization conditions. This is associated with the perfect lattice matching between the beta-form PBA and PE crystals and can provide us a simple way to control the crystalline modification of PBA during different processing process in order to regulate its crystal size.