In this paper, we shall discuss a possible method to obtain four momentum transfer, Δ2, and the transverse momentum, PT, of the recoil proton concerned to high energy jet showers. Up to the present, any confidential result has not yet been got because of many difficulties in the experiments. A method has been studied by C. Kim with respect to the systematic survey of the composition of the secondary particles emitted in the backward cone. Even in his direct method, the discrimination of particles and the energy determination are also yet difficult if particle energy exceeds preminimum regions. In this note, we shall present a method to identify the recoil proton among secondary thin tracks and obtain Δ2 and PT, using a full knowledge of kinematics. In §2, formulae for obtaining Δ2 and PT of the recoil proton shall be introduced. In §3, we shall discuss a method to discriminate recoil proton among secondary thin tracks, taking into account the experimental knowledge of the behavior of secondary pions. Section 4 will be devoted to the practical analysis of experimental data published up to date. We shall discuss, in §5, the results here studied. PT distribution will be presented for 19 jets of KM ≤ 0.2 which are identified as the recoil proton with good reliability, and it shows a fairly large value, different from the case of secondary pion.