P300 component of the event-related brain potential (ERP) reflects fundamental cognitive processes. The P300 components have been employed in a wide variety of theoretical, empirical, and clinical applications. In oddball paradigm for eliciting P300, we need standard stimuli and target stimuli. Firstly, designated stimuli are presented to subjects. Nextly, a chosen target stimulus is presented. In this paper, we elicited the P300 components with experiment that the subjects select a chosen target stimulus. Therefore, we measured the P300 components to be related choice of the target stimuli. The experimental results and the P300 components to be analyzed were presented.