Abstract: Due to the high spatial and time resolution, Broadband Acoustic Doppler Current Profile(BBADCP) has a comprehensive application in hydrology, transportation, measurement controlling etc.The maximum working range is significant for the application.According to Active sonar equation, the influence of depth cell size、temperature and frequency on the working range of BBADCP is analyzed.The theoretical calculation of the maximum working range of BBADCP is made.Comparing the calculated results with the datasheet of RDI BBADCP shows that the working ranges are identical.In addition, the differences of working range between Acoustic Correlation Log、Doppler Velocity Log、Narrowband ADCP and Broadband ADCP are also compared.