Black and White aerial photogrphs are much useful to obtain the information on the channel - bed fluctuation in the following aspects. 1. In the decision of river width, the linear regression formula between the value of aerial photograph interpretation and that of field surveying is Y =1.0+0.94X(the decision coefficient is r²=0.98). Therefore, aerial photographs are proved effective for the measurement of river width. 2. Aerial photograph interpretation makes it possible to classify the plane channel and the deposits in river, and suggests the situation of the plane distribution of deposits, the size of channel and the course of channel formation. 3. The periodical channel situation can be figured out through the interpretation of aerial photographs pictured in different times. Also, the comparing and analyzing each interpretated information can be able to guess the course of the variation of channel influencing powerfully channel-bed fluctuation. 4. The microtopographic map of river can be made through the decision of river with, the interpretation of the plane shape of channel bed and the analysis of variation of channel. On the basis of this map, the plane analysis of deposit is possible.