  We investigate the generalized monogamy and polygamy relations $N$-qubit
systems. We give a general upper bound of the $\alpha$th ($0\leq\alpha\leq2$)
power of concurrence for $N$-qubit states. The monogamy relations satisfied by
the $\alpha$th ($0\leq\alpha\leq2$) power of concurrence are presented for
$N$-qubit pure states under the partition $AB$ and $C_1 . . . C_{N-2}$, as well
as under the partition $ABC_1$ and $C_2\cdots C_{N-2}$. These inequalities give
rise to the restrictions on entanglement distribution and the trade off of
entanglement among the subsystems. Similar results are also derived for
negativity.
