Cyclopolymerization of 1,5-hexadiene has been carried out at various temperatures in toluene by using three different stereospecific metallocene catalysts-isospecific rac-(EBI)Zr(NMe2)(2) [EBI: ethylenebis(1-indenyl), Cat 1], syndiospecific Me2C(Cp)(Flu)ZrMe2 (Cp = 1-cyclopentadienyl, Flu 1-fluorenyl, Cat 2), and aspecific Cp-2*ZrMe2 (Cp*: pentamethylcyclopentadienyl, Cat 3) compounds in the presence of Al(i-Bu)(3) and [Ph3C][B(C6F5)(4)-in order to study the effect of polymerization temperature and catalyst stereospecificity on the property and microstructure of poly(methylene-1,3-cyclopentane) (PMCP). The activities of catalysts decrease in the following order: Cat I > Cat 2 > Cat 3. PMCPs produced by Cat 1 are net completely soluble in toluene. but those by Cat 2 and Cat 3 are soluble in toluene. trans-Diisotactic rich PMCPs are produced by Cat I and Cat 2, and cis-atactic PMCP by Cat 3. The cis/trans ratio of PMCP by Cat I and Cat 2 is relatively insensitive to the polymerization temperature, but that by Cat 3 is highly sensitive to the polymerization temperature. Melting temperatures of PMCP produced increase with the cis to trans ratio of rings.