beta-Nucleated polypropylene (PP), uncompatibilized beta-nucleated PP/poly(trimethylene terephthalate) (PTT), beta-nucleated PP/PTT blends compatibilized with maleic anhydride (MA)-grafted PP (PP-g-MA), and styreneethylenepropylene copolymer were prepared with a twin-screw extruder. The morphology, compatibility, crystallization characteristic, melting behavior, and crystallization kinetics were investigated. The result shows that beta-nucleated PP was incompatible with PTT, and the addition of the two compatibilizers decreased the interfacial tension between beta-nucleated PP and PTT; this led to improved dispersion and strengthened interfacial bonding in the blends. PP-g-MA had a better compatibilization effect. All of the researched beta-nucleated PP/PTT blends contained beta crystals of PP, and the compatibilizers exhibited synergistic effects with the beta-nucleating agent to further increase the content of beta crystals. Nonisothermal kinetic analysis indicated that Mo's method described the nonisothermal crystallization behavior of the beta-nucleated PP/PTT blends satisfactorily, and the Avrami approach could only describe the early stage of the crystallization appropriately, whereas the Ozawa method failed to have the same effect. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012