A scheme of using a mode-locked fiber ring laser and taking the advantage of the time unevenness of the multiplexed signal to obtain the clock of the single channel from the optical time division multiplexing (OTDM) signal is proposed. In experiment, the electronic time division multiplexing (TDM) signal is used because it is identical with OTDM signal in principle. The optical clock of the single channel is obtained successfully using the electronic multiplexed signal. The result can be applied in all-optical clock recovery of the OTDM system.