Abstract: Quantum computation, based on quantum state superposition and entanglement, offered a new computing schema for its  exponentially grown huge computing space and higher information abstracting ability. It can potentially solve a series of problems
that is “hard” for classical computer, and significantly decrease the power consumption per operation. Superconductivity, as a robust
macroscopic quantum phenomenon, offered a perfect non-dissipating test-bed for coherent quantum operation. Moreover, Josephson
junction that based on superconductors offered essential state quantization and non-linearity for constructing a qubit. After over twenty
year’s fast development, quantum computing technology based on superconducting quantum circuits has achieved abundant breaks in
some key technologies, including improvement of coherence time, quantum state manipulation and readout, tunable coupling between
qubits, scaling up to well addressable moderate-large scale quantum system, and so on. Now, it is no doubt that superconducting
quantum computing becomes one of the most promising candidates for building a universal quantum computer. Here I would like
to give a crash review for this technology, and briefly draw a skeleton of superconducting quantum circuits. The purpose is to let the
readers catch some scientific backend for building a quantum computer. Therefore, I try the best to avoid complicated symbols and
equations. Finally, I try to give a bold discussion about the future development blueprint, and point out some key technical challenges
when approaching such a “Holy Grail”.

Key words: quantum computing, superconducting qubit, quantum circuit, Josephson junction, quantum simulation