Cancers are one of the main causes of human deaths globally. Great effort has been dedicated to the search for sensitive and specific markers of cancer. Polyamines including mainly putrescine (PUT), spermidine (SPD), and spermine (SP), are promising tumor markers since their excretion is frequently elevated in patients with various types of cancers. In the present study, we developed an efficient high performance liquid chromatographic (HPLC) method for the determination of polyamines in human serum using dansyl chloride for pre-column derivatization. All polyamines were separated within 10 min. The analytical method is simple, rapid, and highly reproducible. We applied of 11 cancers as objects of study, and made comparisons between polyamines and other 24 common tumor markers with six indexes: specificity, sensitivity, negative predictive value, positive predictive value, total effective, and the mean value. We drew the conclusion that polyamines are promising tumor markers, and they might be of great value in diagnosing cancers, predicting therapeutic success, or indicating the relapse of tumors.