Attributed to the extensive researches towards the functions of Kv1.5 gene (also known as KCN5A gene), the therapeutic significances of Kv1.5 channel have been paid special attentions to cardiovascular diseases as well as tumor, the top two public-health problems for the aging population. During recent years, the hindrance for developing cardiovascular drugs is how to discriminate their therapeutic effect from cardiotoxicities. Therefore, targeting Kv1.5 gene, which encodes the atrial selective I(Kur) potassium channel, has been confirmed as an appealing strategy for the treatment of atrial diseases. Moreover, the functions of Kv1.5 gene in carcinoma progression have also provoked a flurry of research in the hope of developing adjunctive or combined treatment of Kv1.5 modulators to enhance curative effects of classic chemotherapeutic agents.