Abstract: In this article, we derive the explicit entanglement and fidelity expressions for a larger class of two-qubit states, namely, a seven-parameter family of so called X-states. The analytical expressions of the entanglement, the output entanglement and the average fidelity are obtained for this general model by using the concept of concurrence and average fidelity. We study the relations between quantum entanglement, the output entanglement, and the average fidelity for standard teleportation of one-qubit and partial teleportation of two-qubit state. We discover that the average fidelity and entanglement is not a simple dependence relation. The higher entangled system is helpful for teleportation.

Key words: X-states, entanglement, teleportation