The test group and control group, which were grouped with the same weight of five frogs (Rana nigromaculata) respectively, were adapted to light for two hours. Then the anterior lymph heart of the test group were injected with 0.5 cc of 0.1% acetyl choline and 0.5cc of Vitamin B12 (50mc gm/cc). After the frogs of this group were dark-adapted for 90 minutes, their heads were cut off under the dim red light and then their retina removed from eye-balls were extracted with 2% digitonin solution for 20 hours at $0^{circ}C$. The results of the comparison of these two groups whose optical densities were measured before and after the illumination areas follows : (1) The group which had been injected with 0.5cc of 0.1% acetyl choline solution had the protomotive action on the regeneration of rhodopsin in comparison with the control group. (2) The group which had been injected with 25 mc gm of Vitamin B12 and 0.5cc of 0.1% acetyl choline solution had the controlling action on the regeneration of rhodopsin in comparison with the control group.