Non-perturbative renormalization of Nf=2+1 QCD with Schroedinger functional scheme

We present a preliminary result of Nf=2+1 QCD running coupling in Schroedinger functional scheme. We adopted Iwasaki gauge action and non-perturbatively improved Wilson fermion action with clover term. We use seven renormalization scales to cover from low energy to high energy perturbative region and three lattice spacings to take the continuum limit at each scale. A scaling behabior of the step scaling function is discussed together with its renoralization group flow in the continuum. We argue on introduction of the physical scale through the Sommer scale r0.