  By using the "subtracting projectors" method in proving the separability of
PPT states on multiple quantum spaces, we derive a canonical form of PPT states
in ${\Cb}^{K_1} \otimes {\Cb}^{K_2} \otimes ... \otimes {\Cb}^{K_m} \otimes
{\Cb}^N$ composite quantum systems with rank $N$, from which a sufficient
separability condition for these states is presented.
