The role of N-linked glycosylation and various domains of the fusion (F) protein of bovine respiratory syncytial virus strain A51908 during transport to the cell surface were determined by mutating the four glycosylation sites and by constructing various truncation mutants. The cell surface expression of various mutant proteins was detected by surface immunofluorescence and cell surface biotinylation assay. We found that the glycosylation at positions Gly1, Gly2, Gly3, and a truncation mutant with a cytoplasmic domain deletion play little or no role in transport to cell surface. However, glycosylation at position Gly4, and the truncation mutants having deletion in the signal peptide, the F2 + signal peptide domain, and the membrane anchor domain, had impaired transport to the cell surface. This indicated the importance of these glycosylation sites and domains in facilitating the transport of the F protein to the cell surface.