Antifreeze proteins are also defined as thermal hysteresis proteins. They are one kind of functional proteins discovered in many organisms. When the temperature is subzero, they can bind to the surface of the ice nucleations to restrict their growth so as to protect organisms from injury caused by freezing. Insect antifreeze proteins have special structures such as repeat sequences, β-helix and TXT motifs. Additionally, they have stronger antifreeze activity than antifreeze proteins of other organisms. In this article, the special properties of insect antifreeze protein are introduced in detail; new advances on their structure and molecular biology are reviewed. Meanwhile, the function of TXT motif and the relationship between structure and function are discussed.