  We study how a chiral tricritical point (TCP) on QCD phase diagram is
affected by the imbalance of up and down quark densities (isospin density),
using the generalized Ginzburg-Landau (GL) approach. The resulting phase
diagram near TCP shows a rich fine structure which includes inhomogeneities of
both the chiral and the charged pion condensations. It turns out that the TCP
splits into multicritical points.
