Rice is Japanese staple food and is familiar to the public. When rice grains are found at a crime scene as evidence, the identification or discrimination of the rice cultivar is required during any forensic examination. An identification kit of rice cultivars has already been commercially available. To apply the kit to the forensic examination, we determined whether the kit could identify rice cultivars available on the market. In this study, various cultivars of white rice purchased on the market were analyzed by the commercial identification kit, "Kome-Bugyou" (Kokken Corporation), from a single rice grain sample so as to confirm the effectivity of the commercial identification kit and the validity of the labeling of products. Brown rice and boiled rice were also collected and analyzed to determine whether the method of identifying the cultivars of white rice could be applicable to that of brown rice and boiled rice. As a result, DNAs of the rice cultivar other than indicated on the label were detected in some products, but many products contained pure breeds. Cultivars of brown rice and boiled rice could also be identified by the same method as analyzing white rice. Considering the unintended grain contamination or PCR repeatability, more than one PCR analysis should be performed per sample to differentiate cultivars more exactly. It became clear that the commercially available identification kit was useful to differentiate rice cultivars available on the market, and this method was effective in forensic examination.