Abstract: The performance of wax deposits both in static and dynamic conditions and the pourpoint of PuLing crude at same conditions are evaluated using a tubular apparatus.It is found that after the crude is treated by additive"EVA", there is a difference in changes of the deposition and flow characteristics.That is, the depressant effects on wax deposits strength strictly dependent on treating Condition and temperature of crude oil.The necessity for establishing a criterion is emphasized.In making the criterion, account must be taken of both deposition and flow characteristics based on pipeline temperature for selecting optimum thermal treating temperature.