Activation parameters of the exchange between two types of glycinate groups in (nitrilotriacetato)dioxovanadate(V) ion, $[VO_2(NTA)]^{2-}$, have been determined as the results of $^{13}C$ NMR measurements over a range of temperatures between 277 and 306$^{circ}K$. The exchange mechanism is proposed on the basis of the chelate ring opening-closing process, assuming rupture of the metal-oxygen (glycinate) bond trans to V = O bond to give a five-coordinated intermediate.