It is thought that critical thinking ability is an important element for achieving a democratic society. Good instruments for assessing critical thinking ability can be used not only to understand the critical thinking quality of general citizen, but also to inform instructional strategy based on their results. Recently it has become more popular to use critical thinking instruments on research in the elementary, junior, college students, and even adults. There is a need to carry out a comprehensive introduction and analysis on these instruments. Therefore, the paper aims to analyze several often-used instruments and the paper which used those instruments, and finally, recommendations based on the analysis are provided.