  The critical endpoint (CEP) and the phase structure are studied in the
Polyakov-loop extended Nambu--Jona-Lasinio model in which the scalar type
eight-quark (\sigma^4) interaction and the vector type four-quark interaction
are newly added. The \sigma^4 interaction largely shifts the CEP toward higher
temperature and lower chemical potential, while the vector type interaction
does oppositely. At zero chemical potential, the \sigma^4 interaction moves the
pseudo-critical temperature of the chiral phase transition to the vicinity of
that of the deconfinement phase transition.
