  We develop a novel method in classifying the multipartite entanglement state
of $2\times N\times N$ under stochastic local operation and classical
communication. In this method, all inequivalent classes of true entangled state
can be assorted directly without knowing the classification information of
lower dimension ones for any given dimension $N$. It also gives a nature
explanation for the non-local parameters remaining in the entanglement classes
while $N\geq 4$ .
