Abstract: Preferential flow ( PF) resulted from soil heterogeneity is an ordinary form of water movement，which has significance on study both environment and human health because it transports contaminant to deeper soil even groundwater without physical － chemical and biological interaction within the upper layer of soil． There were various Preferential flow( PF) processes occur in soil，and it was difficult to be measured and quantified． So there weren’t many researches paying attention to it until recent decades． This paper introduced the definition，characteristics and manifestation of preferential flow( PF) ，and compared techniques which commonly used in preferential flow( PF) studying now． Techniques such as simple excavation and profiles observation，dye tracing and so on，are easy，inexpensive and no time consuming，but has no regional characteristics． X － ray scanning and microscopic imaging techniques can quantify macropores in soil core and profile，it can attain microcosmic scale ranged from 10 － 6 to 10 － 1 m，but it is expensive and professional technicians are needed for the operation of instrument． The current state of knowledge is inadequate in continuity measuring preferential flow( PF) in the field and on lager scale without soil disturbance． Furthermore，comparing data obtained with different approaches or different initial conditions would bring new information on a large number of studies，and standardized and systematic studyingmethods are necessary for improving the research of preferential flow( PF).