  The dynamical behaviors of FRW Universe containing a posivive/negative
potential scalar field in loop quantum cosmology scenario are discussed. The
method of the phase-plane analysis is used to investigate the stability of the
Universe. It is found that the stability properties in this situation are quite
different from the classical cosmology case. For a positive potential scalar
field coupled with a barotropic fluid, the cosmological autonomous system has
five fixed points and one of them is stable if the adiabatic index $\gamma$
satisfies $0<\gamma<2$. This leads to the fact that the universe just have one
bounce point instead of the singularity which lies in the quantum dominated
area and it is caused by the quantum geometry effect. There are four fixed
points if one considers a scalar field with a negative potential, but none of
them is stable. Therefore, the universe has two kinds of bounce points, one is
caused by the quantum geometry effect and the other is caused by the negative
potential, the Universe may enter a classical re-collapse after the quantum
bounce. This hints that the spatially flat FRW Universe containing a negative
potential scalar field is cyclic.
