[en] The effect of replacement Cu by V in La_2-xSr_xCuO_4+δ system has been studied in this paper. XRD analysis shows that La_1.85Sr_0.15Cu_1-xV_xO_4+δ keeps tetragonal structure with the concentration of V increasing from 0.0 to 0.15. Resistance and Meissner measurement show that the substitution of V will destroy the superconductivity in this system. The well-defined 'T_c-onset' systematically shifts to lower temperature with increasing V concentration and disappears at x=0.15. It is much higher than that of the La_1.85Sr_0.15Cu_1-xM_xO_4+δ (M=Fe, Co, Ni, Zn, Mg, Al and Ga) systems, in which T_c's disappear when x are small (x=0.04 at most). A possible explanation for this phenomenon is presented