  We use the Jeans equations for an ensemble of collisionless particles to
describe the distribution of broad-line region (BLR) cloud in three classes:
(A) non disc (B) disc-wind (c) pure disc structure. We propose that clumpy
structures in the brightest quasars belong to class A, fainter quasars and
brighter Seyferts belong to class B, and dimmer Seyfert galaxies and all
low-luminosity AGNs (LLAGNs) belong to class C. We derive the virial factor,
$f$, for disc-like structures and find a negative correlation between the
inclination angle, $\theta_{0}$, and $f$. We find similar behaviour for $f$ as
a function of the FWHM and $\sigma_{z}$, the $z$ component of velocity
dispersion. For different values of $\theta_{0}$ we find that $ 1.0 \lesssim f
\lesssim 9.0 $ in type1 AGNs and $ 0.5 \lesssim f \lesssim 1.0 $ in type2 AGNs.
Moreover we have $ 0.5 \lesssim f \lesssim 6.5 $ for different values of FWHM
and $ 1.4 \lesssim f \lesssim 1.8 $ for different values of $ \sigma_{z} $. We
also find that $ f $ is relatively insensitive to the variations of bolometric
luminosity and column density of each cloud and the range of variation of $ f $
is in order of 0.01. Considering wide range of $ f $ we see the use of average
virial factor $ \langle f \rangle $ is not very safe. Therefore we propose AGN
community to divide a sample into a few subsamples based on the value of $
\theta_{0}$ and FWHM of members and calculate $ \langle f \rangle $ for each
group separately to reduce uncertainty in black hole mass estimation.
