  Let $f(\bfz,\bar\bfz)$ be a mixed polar homogeneous polynomial of $n$
variables $\bfz=(z_1,..., z_n)$. It defines a projective real algebraic variety
$V:=\{[\bfz]\in \BC\BP^{n-1} | f(\bfz,\bar\bfz)=0 \}$ in the projective space
$\BC\BP^{n-1}$. The behavior is different from that of the projective
hypersurface. The topology is not uniquely determined by the degree of the
variety even if $V$ is non-singular. We study a basic property of such a
variety.
