The use of the serum protein capillary electrophoresis (CE) is prevalent in clinical laboratories owing to its greater feasibility for automation compared with the gel-based methods. Compared with the traditionally commonly used agarose gel electrophoresis, CE exhibits distinctive test principle and technical characteristics, thereby showing different test problems and electrophoretogram characteristics. Proficient comprehension of these properties facilitates the resolution of diverse test problems and verification of results. Electrophoretogram of CE may manifest diverse abnormal peaks beyond monoclonal immunoglobulin protein. Interpreter should understand their characteristics and respond appropriately to abnormal results. To accurately interpret the serum protein CE test, the interpreter would be required to understand the test method and gain experience with various cases through appropriate training.