  The variability of optical FeII blends in NGC 4051 is examined from spectra
extracted from the AGN Watch program.In our analysis, the FeII complex are
subtracted and measured with the following results. Firstly, the FeII
variations were detected in NGC 4051 during a 3-year period. The identified
FeII variations followed the variations in continuum closely. Secondly, the EW
of FeII is reported to increase with the rising continuum flux, which is
consistent with previous claims that there is no convincing Baldwin Effect in
optical FeII. Thirdly, by comparing the variations of H$\beta$ and FeII, we
find that RFe scales with continuum flux as $\rm{R_{Fe}\propto (5.0\pm0.8)
\log(L/M)}$, which is significantly different from the theoretical
expectations. Finally, in six selected Seyferts, four out of five Narrow-Line
Seyfert 1 galaxies present positive correlation between RFe and the continuum
flux. The negative correlations are identified in the remaindng two objects
that have relatively broad profiles of H$\beta$ ($\rm{FWHM>1500 km\
s^{-1}}$).We argue that the difference of electron density of broad line clouds
and/or variability behavior of incident high-energy radiation can explain the
dichotomy in variability behavior of RFe.
