N-glycosylation not only influences the folding and secretion of glycoproteins such as HA and NA but also provides the same glycans (similar to the host's own glycans) to escape the host's immune system. As the key modification of biological significance in viral glycoproteins, we found the glycosites in 17 known HA subtypes and 10 known NA subtypes that have complex characteristics. In general, two highly conserved glycosites near the HA0 cleavage site and fusion peptide site may maintain the basic function of HA; these sites were seldom absent in the HA subtypes. More glycosites were identified in the global domain or in the connection of global and stalk domains, along with longterm and large-scale epidemics in several of the subtypes. The distributional regularity of the glycosites in the NA subtypes is also complex; two to four glycosites located in the stalk domain are highly conserved in various subtypes, and are affected by the deletion of the stalk domain. Another highly conserved glycosite was found at the tip of tetramer NA in all subtypes. Other glycosites were found to be mainly concentrated in the global domain, which surrounds the antigenic sites.