17 Lagrangian. We found that the time component of “ ω ” meson has a VEV for any µ$_{B}$ , as in the ordinary three-color QCD. As a result, the phase structure is the same as the one determined by including only the pseudo-NG bosons [3]: For µ$_{B}$ > M$_{π}$ , the baryonic pion ( J P = 0 + state) condenses, which causes the spontaneous breaking of the baryon number symmetry, U (1)$_{B}$. We investigated the µ$_{B}$ -dependences of the “vector” boson masses and found that the mass of anti-baryon with J P = 1 + ( V$_{B}$$_{−}$ ) increases for µ$_{B}$ < M$_{π}$ and turns to decrease for µ$_{B}$ > M$_{π}$ . The mass of baryon with J P = 1 + ( V$_{B}$$_{+}$ ) shows the opposite behavior. These behaviors of the baryons signal the phase transition of U (1)$_{B}$ breaking in two-color QCD at finite density. At the leading order the vector mesons with J P = 1 − ( ρ and ω mesons) do not change their masses at all. Furthermore, V$_{B}$$_{−}$ does not mix with V$_{B}$$_{+}$ , even though the baryon number U (1)$_{B}$ symmetry is spontaneously broken for µ$_{B}$ > M$_{π}$ . We studied the effects of higher order terms and obtained the corrections to the masses of the “vector” bosons. We assumed that the vacuum structure is not changed, which left only two free parameters C$_{1}$ and C$_{2}$ : The positive (negative) C$_{2}$ provides a negative (positive) contribution to all the “vector” boson masses equally. On the other hand, the effect of nonzero C$_{1}$ produces the mass difference between m$_{ρ}$ and m$_{ω}$ , and this difference is linked to the mixing strength between V$_{B}$$_{+}$ and V$_{B}$$_{−}$ . This relation is obtained from the symmetry breaking pattern and the assumption that all the bosons other than π and V are heavy enough to be neglected in the Lagrangian. Thus, a violation of this relation (Eq. (4.9)) may signal a new phase transition. Comparison with the lattice data in Ref. [7] strongly suggests that there is a large mixing among A , V$_{B}$$_{+}$ and V$_{B}$$_{−}$ for heavy π s such as the one adopted in Ref. [7]. This indicates that the mass of isovector meson with J P = 1 + shown in FIG. 2 of Ref. [7] is nothing but m$_{V}$$_{B}$$_{+}$ observed through the large mixing. We make a comment on the analysis done in Ref. [8]. When the “axial-vector” bosons are taken to be heavy in their model and integrated out, the model becomes identical to the HLS model with the parameter choice C$_{1}$ = C$_{2}$ = 2( M$_{S}$/M$_{X}$ ) $^{4}$/g$^{2}$, where M$_{S}$ and M$_{X}$ express the masses of “vector” bosons and “axial-vector” bosons in their model. As can be seen easily from Eq. (4.6), the choice C$_{1}$ = C$_{2}$ implies that the ρ meson mass m$_{ρ}$ is stable against the density as shown in Ref. [8].