We discuss the flavor number dependence of QCD at low temperature and high density by the complex Langevin method.
In our previous work, the complex Langevin method is confirmed to satisfy the criterion for correct convergence in certain regions, such as $\mu_{\rm q} / T = 5.2-7.2$ on $8^3 \times 16$ and $\mu_{\rm q} / T = 1.6-9.6$ on $16^3 \times 32$ using $N_{\rm f} = 4$ staggered fermion at $\beta = 5.7$.
We extend this study to more realistic flavor cases, $N_{\rm f} = 2, 2 + 1, 3$, using Wilson fermions.
We present the flavor number dependence of the validity regions of the complex Langevin method and the quark number.