The nucleating effects of varying amounts of bicyclic [2.2.1] heptane di-carboxylate (HPN-68) on the mechanical properties and crystallization of polypropylene (PP) have been investigated. It was found that the nucleating agent HPN-68 played a role as a crystallization growth point, which controlled the volume of crystallization and led to an enhancement in the properties of PP. The flexural strength, elasticity modulus and tensile strength of PP were increased by 21%, 25% and 5.56% respectively; there was a decline in impact strength however. The peak temperature of crystallization was increased from 119℃ to 136℃, and the thermal distortion temperature was raised by 19℃. These results showed that HPN-68 is an excellent nucleating agent for enhancing the rigidity of PP.