The existence of a resonance in K-K pair with a mass of 1.02 BeV has been recently observed in π--p and K--p collisions. In several reports the quantum numbers in this resonant state have been determined, but the results are different from one another. From the field theoretical point of view and by means of the chain approximation, we have calculated the interaction potential of K-K system and indicated that there is a resonance in 1.02 BeV T=0,JPG=0++.