Galanthus nivalis agglutinin (GNA)-related lectin family, a superfamily of strictly mannose-binding specific lectins widespread among monotyledonous plants, is well-known to possess a broad range of biological functions such as anti-tumor, anti-fungal and anti-viral activities. Growing insights into the investigations of them provide us a principal force to start this review with a variety of evidences to landmark their biological activities, molecular mechanisms and potential therapeutic applications. Herein, we mainly focused on a comprehensive study on a great number of reported GNA-related lectins with the anti-tumor activity. On the trail of such clues, we studied some GNA-related lectins with anti-tumor effects and explored the apoptosis- and autophagy-induced activities and related molecular mechanisms. These inspiring results further provide us more convincing evidence to understand the anti-cancer molecular mechanisms implicated in apoptosis and autophagy. In addition, GNA-related lectins also possess marked anti-HIV activities and the specific molecular mechanisms are also explored herein. To sum up, GNA-related lectin family would play a key role as a potential drug in future therapeutics.