Using low voltage power line as communication channel，its channel characteristics will affect the quality of communication greatly.This paper analyses low voltage power line channel and channel modeling, in order to supply theoretical foundation for power line communication study. Based on the analysing and generalizing scientific data, this paper concludes that power line channel input impedance presents ascend trend following frequency arising, power line channel noise is repeated addition by varied noise sources, power line signal attenuation is the function of distance and related to frequency, and quantity modeling is impossible. Depending on the study of this paper, low voltage power line communication should select proper frequency channel and adopt modulation system possessing strong anti-interference characteristics.