Abstract: Shear efleet,during long—distance pipelining, can worsen the improved rheological properties of PPD-treated waxv crude oils.To solve the problem of shearing reliability of the PPD-beneficiated waxy crude oils, a breakthrough in mechanism research has to be made.This paper, on the basis of summarizing the research situation at home and abroad, by analyzing the common problems we have to confront, i.e. weakness in basic theory study, multifactors affecting experimental data and inconsistent conditional experiment methods in three aspects of the studies from intermolecular forces, the interaction of colloidal particles and crude oil rheology, suggestions to carry out more research on basic theories, don't restrict on curre!nt research conclusions and conduct comprehensive multi—disciplinary researches are put forward.