With the advances in digital video technology, it is becoming easier to forge the digital video without introducing any artificial visual trace. The temporal domain of the digital videos is one of the main targets of video tampering, and video frame-rate conversion is one of the common operations for temporal video tampering such as temporal splicing and video speed adjustment. This operation necessarily accommodates temporal interpolation that introduces the periodic motion artifact on the motion trajectories. In this paper, the frame-rate converted video detection method is proposed based on the motion artifact. The experimental results demonstrated the performance of the proposed method through the extensive experiments on 1300 original videos and 18,000 frame-rate converted videos in uncompressed and H.264/AVC formats. Especially, for the nearest neighbor and motion-based interpolation, the proposed method could detect over than 93.35% of the frame-rate up-converted videos while exhibiting 0.01 false positive rate.