We have performed a detailed multifractal analysis on the daily streamflow series of the Yangtze River from 1940 to 1992. The partition function ??q(??), exponent function ??q, generalized fractal dimensions Dq, singularity ?? and multifractal spectrum f(??) are calculated. It is found that the partition function ??q(??) scales as a power law with respect to the box size ?? and the whole series and every annual series obey multifractal scaling, rather than being a simple monofractal. Furthermore, the range of singularity ?? of the annual series reach minimum value in 1988 and maximum value in 1974, which indicated that the series of 1988 variation is smallest and the series of 1974 variation is largest.
