Abstract: Transfer law of startup pressure wave in crude oil inside the pipe is researched by means of a DN300 Commercial Test Loop. Transfer velocity of startup pressure wave in crude oil is measured at different operating conditions,and influencing factors of startup flowrate,OiI temperature before shutdown and startup transportation temperature are analyzed. ExperimentaI and theoretical analyses show that influence law in cooling contractibility of crude oil and structure characteristic of gel crude oil itself on transfer of startup pressure wave can be more directly reflected through utilizing relative parameters such as wax deposited point temperature of crude oil and oil temperatures of pipeline at shutdown/startup. Simple form mathematical model for startup pressure wave transfer velocity is obtained through mathematical regression based on experimental data of the large-scale loop.