  We calculated a grid of evolutionary tracks of rotating models with masses
between 1.0 and 3.0 $M_{\odot}$ and a resolution $\delta M \leq 0.02$
$M_{\odot}$, which can be used to study the effects of rotation on stellar
evolutions and on the characteristics of star clusters. The value of $\sim$2.05
$M_{\odot}$ is a critical mass for the effects of rotation on stellar structure
and evolution. For stars with $M >$ 2.05 $M_{\odot}$, rotation leads to an
increase in the convective core and prolongs the lifetime of main sequence
(MS); rotating models evolve slower than non-rotating ones; the effects of
rotation on the evolution of these stars are similar to those of convective
core overshooting. However for stars with 1.1 $< M/M_{\odot}<$ 2.05, rotation
results in a decrease in the convective core and shortens the lifetime of MS;
rotating models evolve faster than non-rotating ones. When the mass is located
in the range of $\sim$1.7 - 2.0 $M_{\odot}$, the mixing caused by rotationally
induced instabilities is not efficient; the hydrostatic effects dominate the
effect on the evolution of these stars. For the models with masses between
about 1.6 and 2.0 $M_{\odot}$, rotating models always exhibit lower effective
temperatures than non-rotating ones at the same age during the MS stage. For a
given age, the lower the mass, the smaller the change in the effective
temperature. Thus rotations could lead to a color spread near the MS turnoff in
the color-magnitude diagram for the intermediate-age star clusters.
