In this paper, a new application manner by on line analyses for the stacked spectral plots (SSP) in the control & dwell display window of boundary wind profiler (BWP) obtained during the rainfall time periods has been introduced. The paper has described the principle and method of BWP on line analyses in detail, and by combined with some typical cases of precipitation SSP analyses, the evidences of potential parameters extracted from SSP have been presented. The advantages and benefits for implementation on line analyses on SSP of precipitation, including extension application fields of BWP from clear air to rainfall weather, mitigation current BWP’s application bottle neck, as well as indirect verification of the standpoint for non constant interval distance in BWP networking, have been indicated. It is believed that during the precipitation time sections BWP will be a very important tool for the weather stations to carry out detailed weather surveillance and forecast/service with the manner application and expansion of on line analyses of BWP.