The sustainment of the high normalized beta value N has progressed remarkably in JT-60U. N=3 was sustained for 6.2s and N=2.5 for 15.5s, and N=2.1 for 20 s, only interrupted by the capability of neutral beam heating system (power and pulse length), not by the plasma stability, with low safety factor (q95=2.2, 3.4, and 3.2, respectively). In the case of N=2.1, in particular, the current profile reached a steady state. In this low safety factor regime, the resonant surfaces with q=3/2 and 2/1 were shifted outside the steep pressure gradient layer, stabilizing the neoclassical tearing mode (NTM) above the previous N-limit imposed by NTMs. To establish the feedback control of the safety factor profile q( ), a real-time q( ) control system has been developed using the motional Stark effect (MSE) diagnostic as detector and the lower hybrid current drive (LHCD) as actuator. For the first time, real-time feedback control has been demonstrated based on local pitch angle measurement and control of parallel refractive index of LH waves adjusting the LHCD location.