Recent observations of barred spiral galaxies have shown that forming stars in bar regions is more difficult than in arms even when both regions have similar surface density of gas. However, the mechanism is not well understood yet. We perform a simulation of a barred spiral galaxy to investigate whether the star formation criteria used in cosmological simulations can reproduce the observational trends or not. The criteria are that gas can be converted into stars when the gas is dense, cool, and locally self-gravitating. Our result shows that the criteria cannot reproduce the suppression of star formation in the bar region. This means that we need to introduce better models for star formation in galaxy simulations. In addition, we find that almost all gas which is dense and cool in bar and arm regions is self-gravitationally bound.