The morphology and crytal structure of poly(p-phenylene terephthalate) (PPT), prepared by confined thin filmmelt (CTFMP) and solution (CTFSP) and bulk solution polymerization, were characterized by transmission electronmicroscopy, electron dimaction and molecular modeling. The unit cell is monoclinic (P2_1/a space group) with parameters a =7.89, b = 5.49, c = 12.65 A, α=γ= 90°, β=100.33°, density = 1.48 g/cm~3, the a, b and β values differing slightly from thosereported previously in the literature. A degree of variation in relative intensities of hk0 reflections in, apparently, untilted[001] ED patterns was observed from a given sample, suggesting some variation in molecular packing. ED evidence wasfound for a second phase, with [001] appearing the same as for phase Ⅱ of the related poly(p-oxybenzoate) (PpOBA)polymer. CTFMP crystals polymerized above 220℃ (up to 370℃) and CTFSP crystals polymerized at 300℃ consisted oflamellae 100-200 A thick. The morphology and crytal structure of poly (p-phenylene terephthalate) (PPT), prepared by confined thin film melt (CTFMP) and solution (CTFSP) and bulk solution polymerization, were characterized by transmission electron microscopy, electron dimaction and molecular modeling. is monoclinic (P2_1 / a space group) with parameters a = 7.89, b = 5.49, c = 12.65 A, α = γ = 90 °, β = 100.33 °, density = 1.48 g / cm 3, the a, b and β degrees differing slightly from those previously ported in the literature. A degree of variation in relative intensities of hk0 reflections in, apparently, untilted [001] ED patterns was observed from a given sample, suggesting some variation in molecular packing. second phase, with [001] appearing the same as for phase II of the related poly (p-oxybenzoate) (PpOBA) polymer. CTFMP crystals polymerized above 220 ° C up to 370 ° C and CTFSP crystals polymerized at 300 ° C consisted oflamellae 100 -200 A thick.