[en] Once the quark chemical potential μ is introduced in finite density QCD, the fermion determinant appeared in the path integral measure becomes complex. In order to investigate the phase effect of SU(3) lattice QCD (2-flavors), we calculated the fluctuation of the phase of det Δ(μ) on a 8³ x 4 lattice at μ = 0.1 and 0.2. Then we calculated the chiral condensate and Polyakov line in the no phase and reweighted cases. There is little difference between these two cases at μ = 0.1 and 0.2. We consider a possible reason for this result below μ ≤ 0.27 in terms of Z₃ symmetry