To provide a seat reclining device capable of improving the touch of operation by rotating respective cams synchronously by the right and left recliners so as to eliminate the deviation of the timing of unlocking the respective recliners.

The recliners 1 and 1' are provided on the right and lest of a seat bottom, and both of the recliners 1 and 1' are bridged by a cam driving shaft 6 crossing the seat bottom. Two cams 5 are fitted externally to both of the end parts of this shaft 6, and an operation lever 7 is connected to the side of one end of this shaft 6. By operating this lever 7, the driving force of the lever 7 is transmitted directly to the shaft 6 to rotate the shaft 6, thereby the two cams 5 fitted externally to both of the end parts of the shaft 6 are rotated synchronously.