Oligosaccharide aromatic glycoside sulfates and physiologically acceptable salts thereof, are disclosed. Further, antiviral agents having these sulfate compounds as the active components, and particularly an antiviral agent, wherein the virus is one which causes AIDS (Acquired Immune Deficiency Syndrome), are disclosed. The active components or the glycoside sulfates, and the salts thereof, are characterized by an oligosaccharide aromatic glycoside sulfate in which the hydrogen of the position-1 hydroxyl group of the terminal sugar of an oligosaccharide is substituted with a specified formula having an alkyl group consisting of 1 to 18 carbons, an oxygen or no oxygen, and an allylene group. The number of constituent monosaccharides in the oligosaccharide portion is preferably within a range of 2 to 20. Further, 10% or more of the remaining hydroxyl groups of the sugar subunits are subjected to sulfated esterification. In addition the antiviral agent exhibits low toxicity and is useful in the treatment of AIDS. Furthermore, an oligosaccharide is also disclosed as described above with the exception that it is the hydrogen atom of the position 1 hydrogen group at the terminal sugar residue which is substituted with the specified formula, also described above. However, in addition the remaining hydroxyl groups of the sugar portion of this oligosaccharide are protected by acyl groups or are present in an unprotected form. Also disclosed is a method for the production of an oligosaccharide aromatic glycoside sulfate synthesized by sulfation using a sulfating agent.