Transferrin is the major plasma transport protein for iron. We aimed to investigate the characteristics of transferrin variant by carbohydrate-deficient transferrin (CDT) test using capillary zone electrophoresis. We retrospectively analyzed the CDT tests of 2449 patients from March 2009 to May 2017 at a tertiary hospital in Korea. CDT was quantified using a Capillarys 2 system (Sebia, Lisses, France) by capillary zone electrophoresis. The characteristics of variant transferrin patterns using electropherogram of CDT tests were analyzed. Seventy-seven (3.1%) patients were classified as variant transferrin. Mean age of these patients was 51.8years, and the male-to-female ratio was 3.5:1. The most common variants were the BC variants (n=37), followed by the CD variants (n=27), unclear patterns (n=7), BD variants (n=3), CC variants (n=2), misclassification (n=1). In the variant Tf group, the most common disease was alcoholic liver cirrhosis (n=22, 28.6%), followed by the toxic effects of substances (n=17, 22.1%), and mental and behavioral disorders attributable to alcohol (n=11, 14.3%). Nonvariant group showed a predominance of the toxic substance effects (n=880, 37.1%), a personal history of suicide attempts (n=634, 26.7%), and mental and behavioral disorders due to alcohol (n=336, 14.2%). We analyzed the basic characteristics of variant transferrin by CDT tests using capillary zone electrophoresis. The prevalence of variant transferrin was 3.1% of the study subjects. Male patients, alcohol abusers, and liver cirrhosis patients predominated in the variant transferrin population. Further prospective studies are warranted to elucidate variant transferrin in clinical practice.