This document introduces the theory and principles of HPCE, including separation by CE, mobility, electro-osmotic flow, efficiency, and resolution; explains CE instrumentation, such as capillary conditioning and thermostating, sample injection, detection modes of operation; discusses method development strategies, such as buffer selection, sample matrix, peak shape; describes the applications of CE in bioscience, pharmaceutical, environmental, chemical, and food industries; provides practical tips and methods for using CE effectively and accurately.