  We have investigated uudd\sbar pentaquarks by employing quark models with the
meson exchange and the effective gluon exchange as qq and q\qbar interactions.
The system for five quarks is dynamically solved; two quarks are allowed to
have a diquark-like qq correlation. It is found that the lowest mass of the
pentaquark is about 1947 -- 2144 MeV. There are parameter sets where the mass
of the lowest positive-parity state become lower than that of the
negative-parity states. Which parity corresponds to the observed peak is still
an open question. Relative distance of two quarks with the attractive
interaction is found to be by about 1.2 -- 1.3 times closer than that of the
repulsive one. The diquark-like quark correlation seems to play an important
role in the pentaquark systems.
