Abstract: The physical theory of mass analysis has been briefly reviewed. The tools of mass analysis that human used during past thousands years include steelyard, spring scale, balance and mass spectrometer. All of the tools were built based on the physics theories. For example, the steelyard and balance were built based on the Archimedes’ principle. Spring scale was built based on the Hooke’s law of elasticity, and the mass spectrometers were built based on the electromagnetic theory. The mass spectrometers can be used to analyze the species, amounts, functions, and conformations of atoms and molecules. The physics principle of each mass analysis technique was described and the future of mass analysis was discussed.