A new method of determination of safety of antral branches of the vagus nerves during selective proximal vagotomy based on the potentiometric measurement of the oxidation-reduction potential from the side of the serous membrane on the anterior and posterior walls of the antral portion of the stomach was developed in experiments and approved in the clinic. Results of using the method during operation as well as findings of complex investigation of the motor-evacuatory function of the stomach in the nearest and remote terms after vagotomy show efficiency of the method. The method may be recommended for the surgical practice.