Abstract: The effects of Na addition in the MTG-YBCO (YBa _2-x Na _xCu ₃O _y+40mol% Y ₂BaCuO ₅) system with x=0.0, 0.1, 0.2 on the texture and superconducting properties have been investigated. It was observed that there is little change on T _c,on as x ≤0.2 for these materials, but T _c,off decreases with x increase. That is, the larger the Na content in the composition, the broader is the superconducting transition region. With certain Na addition, MTG-YBCO showed an improved critical current density characteristic and a second peak with increasing magnetic field. The post-annealing at 900℃ reduced the critical current density and eliminated the second peak. The followed oxygenation at 400℃ increased the critical current density and recovered the second peak again. These might be connected with the formation of low T_c phase owing to the addition of Na. At the same time, Na doping improved the texture of MTG-YBCO and result in a increase of the crystal growth rate in (ab) plane.