Generalized Monogamy Relations of Concurrence for N-qubit Systems

We present a new kind of monogamous relations based on concurrence and concurrence of assistance. For $N$-qubit systems $AB{C}_1\mathrm{.}\mathrm{.}\mathrm{.}{C}_{N-2}$, the monogamy relations satisfied by the concurrence of $N$-qubit pure states under the partition $AB$ and $C_1\mathrm{.}\mathrm{.}\mathrm{.}{C}_{N-2}$, as well as under the partition $AB{C}_1$ and $C_2\mathrm{.}\mathrm{.}\mathrm{.}{C}_{N-2}$ are established, which give rise to a kind of restrictions on the entanglement distribution and trade off among the subsystems.