Statistical properties of rms mean magnetic fields B of normal stars were investigated based on data from known catalogues of magnetic fields and recent measurements. We study the magnetic field distribution function and find that it has a steep drop in a weak magnetic field region B <400 G. This drop may be connected with a rapid dissipation of the weak stellar magnetic field proposed by Auriere et al. (2007). We have estimated the magnetic fluxes F of all stars with measured magnetic fields and analyze their statistical properties.