  The unified model of Seyfert galaxies suggests that there are hidden
broad-line regions (HBLRs) in Seyfert 2 galaxies (S2s). However, there is
increasing evidence for the appearance of a subclass of S2s lacking of HBLR
(non-HBLR S2s). An interesting issue arises as to relations of non-HBLR S2s
with other types of Seyfert galaxies and whether or not they can be included in
the unified model. We assemble two sub-samples consisting of 42 non-HBLR S2s
and 44 narrow-line Seyfert 1s (NLS1s) with redshift $z\le 0.05$ from published
literatures to explore this issue. We compare black hole masses in the galactic
centers, accretion rates, infrared color ratio ($f_{60 \mu \rm m}/f_{25 \mu \rm
m}$) as a potential indicator of the dusty torus orientation, \oiii $\lambda
5007$, radio and far infrared luminosities. We find that non-HBLR S2s and NLS1s
have: 1) similar distributions of the black hole masses ($10^6-3\times
10^7\sunm$) and the Eddington ratios ($L_{\rm Bol}/L_{\rm Edd}\sim 1$); 2)
significantly different distributions of $f_{60 \mu \rm m}/f_{25 \mu \rm m}$
ratios; 3) similar distributions of bulge magnitudes and luminosities of [O
{\sc iii}], radio, far infrared emission. The similarities and differences can
be understood naturally if they are intrinsically same but non-HBLR S2s are
viewed at larger angles of observer's sight than NLS1s. We thus suggest that
non-HBLR S2s only have "narrower" broad line regions and they are the
counterparts of NLS1s viewed at high inclination angles. The absence of the
polarized emission line in non-HBLR S2s is caused by the less massive black
holes and high accretion rate similar to NLS1s. The implications of the
unification scheme of non-HBLR S2s and NLS1s are discussed.
