Abstract: Aiming to find the effect of components of pour point depressants (PPD′s) on their properties, various analytical methods, including IRS, gel chromatography, super-conducting NMRS, saponification titration and GC-MS, were applied to the componental analysis of 10 samples of home-made and imported PPD′s commonly used for diesel oil. It was found that all of the 10 PPD′s were belonged to the type of polymers of ethylene-vinyl acetate, with relatively low relative molecular mass (Mr<5 500). Contents of polymers of vinyl acetate in the samples were found in the range of (w) 27%-37%. Heavy aromatic hydrocarbons mainly of C10 or their mixtures were used as solvents for the PPD′s. The following differences were found between the domestic and imported samples: ① higher Mr (Mr>3 700) and higher polymer contents (over 30%) for the imported PPD′s; ② small amounts of N-containing dispersing agent were found in the imported products.