Two method to predict targets which a user is about to point with a mouse on the basis of the trajectory of the mouse cursor were proposed. The effects of the interval between targets, the position of targets, the sampling interval and the number of sampling on the pointing time and the prediction accuracy were investigated. In both methods, the distance between targets had little effects on the pointing time. The prediction accuracy was found to be affected by the position of targets. In both prediction methods, the angle between the cursor movement vector and the vector which connects the current cursor position and the center of each target is calculated every st. As for Prediction Method1 that regards the target which correspond to the minimum angle continuously 5 times as the candidate target, the optimal condition of the sampling interval was found to be 0.06 sec or 0.08 sec. Concerning Prediction Method2 that calculates the angle n times and determines the minimum cumulative value as the candidate, the optimal condition of the number of sampling was 8.