  Based on the spectral decomposition through a code of PrepSpec, the light
curves (spanning 6.5 years in the observed frame) of the broad-line Balmer
decrement, i.e., the flux ratio of the broad \ha to the broad \hb line, are
calculated for a sample of 44 Sloan Digital Sky Survey reverberation-mapped
quasars ($z<0.53$). It is found that the logarithm of the mean broad-line
Balmer decrement is 0.62 with a standard deviation of 0.15 dex. The relations
between the mean Balmer decrement and the SMBH accretion properties (the
luminosity, black hole mass, Eddington ratio, accretion rate) are investigated
and no obvious correlations are found. It is found that there are 27 quasars
($61\%$) showing strong negative correlations between the Balmer decrement
variance and the continuum variance, i.e., the Balmer decrement would be
smaller with larger continuum flux. Assuming that the dust obscuration leads to
the variance in the Balmer decrement and the continuum, an expected slope is
$-1/3$, which is not consistent with most of measured slopes. Using the
interpolated cross-correlation function, the time delays between the inverse
Balmer decrement and the continuum are measured for 14 quasars with the maximum
correlation coefficient larger the 0.6. It suggests that the size corresponding
to the Balmer decrement lag extends from the BLR size to the torus size.
