Abstract: The composition and crystal structure of five petroleum waxes (A、B、C、D、E) obtained from Nanyang 3rd and 4th atmospheric side cut, 1st vacuum side cut, 2nd and 3rd vacuum side cut foots oils by ketone benzol dewaxing and deoiling process respectively were analyzed using gas chromatography (GC), differential scanning calorimetry (DSC) and X ray diffraction (XRD). Results showed that the mass fractions of n alkanes in waxes A, B and C were above 90%, while in waxes D, E were about 65% and 30%, respectively. Wax B showed one solid solid transition while waxes A, C, D and E showed two. At room temperature, the crystallization structure was orthorhombic for wax B, hexagonal for waxes A, D and E, and both orthorhombic and hexagonal two phase coexisted for wax C.