<;P>;PROBLEM TO BE SOLVED: To provide a new antiviral agent having an excellent effect and producible inexpensively, especially an anti-HIV agent. <;P>;SOLUTION: This antiviral agent is characterized by using an amino group-non-sulfurated saccharide complex prepared by the reductive amination of the amino group in a molecule having at least &ge;2 amino groups (amino group molecule) and an aldehyde group in the non-sulfurated saccharide or its derivative for bonding them covalently and also having at least &ge;1 free amino group in the amino group molecule after the covalently bonding, as the antiviral agent. <;P>;COPYRIGHT: (C)2010,JPO&INPIT