The crystal defects in diamonds are diverse. In other words, there are almost no perfect diamonds without impurities or dislocations. Most natural diamonds contain a considerable amount of nitrogen impurity in aggregated forms. CVD diamond films also included many crystal defects. We investigated the distribution of luminescence center of natural type Ia diamonds and CVD diamond films by various photoluminescence excitation source. Photoluminescence (PL) spectroscopy is a useful technique to provide information on defects of diamond with high sensitivity.