Abstract: Classified into light, paraffinic base, waxy crude oil, Shanshan crude oil has low gum and asphalt content, and a wax content in which is primarily normal alkane.Urea predewaxing can be easily achieved.According to orthoganal testing method, optimal reaction conditions for laboratory urea predewaxing are determined as follows: one gram of crude oil consumes 0.6g industrial urea under atomspheric pressure, at 25℃, with 1.33 g alcohol, in which 95% is ethanal, as activator (both urea and alcohol can be recycled).After 8 minutes of reaction, the condensation point of the crude oil under dewaxing drops down to -8℃; 90 minutes later, almost all the solid wax can be removed, with only 1.5% left.The dewaxed oil then has a condensation point of -31℃ or less, with its abnormal point of viscosity being 0℃.It remains as Newtonian fluid when the pipeline is buried where the groud tempeture is 2℃.Thus, unheated transportation can be realized all year round.As by-products, liquid wax and paraffin have many uses.