Quantum teleportation transfers an unknown quantum state from one place to another, typically implemented by local joint measurement on entangled channel and classical communication. Generally, it can be understood in the framework of quantum measurement and subsequent reversal. In information-theoretic point of view, it implies the fact that information is conserved during the overall quantum communication process. In this seminar, I will introduce a general framework of quantum teleportation based on quantum measurement process, and provide conditions to find the optimal protocol to transmit a quantum state over arbitrary quantum network. Recent progress on the realization of long distance quantum teleportation will be also introduced.