The role of rotation shear in the internal transport barrier formation is examined by means of a one-dimensional transport simulation based on the current-diffusive ballooning mode turbulence model. Delayed transition to the enhanced improved transport was reproduced in the medium heating power range. The threshold power is strongly reduced by the effect of rotation shear. Simulation including particle transport was also applied to NBI-heated plasmas and the steepness of density and temperature gradients is discussed.