  We carry out a series of high-resolution (1024 X 1024) hydrodynamic
simulations to investigate the orbital evolution of a Saturn-Jupiter pair
embedded in a gaseous disk. This work extends the results of our previous work
by exploring a different orbital configuration---Jupiter lies outside Saturn
(q<1, where q= M_i/M_o is the mass ratio of the inner planet and the outer
one). We focus on the effects of different initial separations (d) between the
two planets and the various surface density profiles of the disk, where \sigma
\propto r^{-\alpha}. We also compare the results of different orbital
configurations of the planet pair. Our results show that: (1) when the initial
separation is relatively large(d>d_{iLr}, where d_{iLr} is the distance between
Jupiter and its first inner Lindblad resonance), the two planets undergo
divergent migration. However, the inward migration of Saturn could be halted
when Jupiter compresses the inner disk in which Saturn is embedded. (2)
Convergent migration occurs when the initial separation is smaller (d<d_{iLr})
and the density slope of the disk is nearly flat (\alpha<1/2). Saturn is then
forced by Jupiter to migrate inward when the two planets are trapped into mean
motion resonances (MMRs), and Saturn may get very close to the central star.
(3) In the case of q<1, the eccentricity of Saturn could be excited to a very
high value (e_{S}~0.4-0.5) by the MMRs and the system could maintain stability.
These results explain the formation of MMRs in the exoplanet systems where the
outer planet is more massive than the inner one. It also helps us to understand
the origin of the "hot Jupiter/Saturn" undergoing high eccentric orbit.
