Crystallization and melting behaviors of isotactic polypropylene (iPP) nucleated with compound nucleating agents of sodium 2,2'-methylene-bis (4,6-di-tertbutylphenyl) phosphate (hereinafter called as NA40)/dicyclohexylterephthalamide (hereinafter called as NABW) (weight ratio of NA40 to NABW is 1:1) were studied by differential scanning calorimetry and wide-angle X-ray diffraction (WAYD), the relative beta-amount of iPP nucleated with these compound nucleating agents was also calculated in Turner-Jones equation by using wide-angle X-ray diffraction data. Under isothermal crystallization, there exists a temperature range favorable for formation of beta-iPP. When the concentration of compound nucleating agents is 0.2 wt %, the temperature range is from 100 to 140 degrees C. While in nonisothermal crystallization, lower cooling rate is favorable for form of beta-iPP and the relative beta-amount of iPP increases with the decreasing of cooling rate in crystallization process. (c) 2008 Wiley Periodicals, Inc.