Laser induced damage threshold (LIDT) of various types of vitreous silica at 1064, 532, 355 and 266 nm were investigated. At 1064 nm no difference of LIDT were observed for all samples. At 1064-355 nm, wavelength dependence of LIDT of synthetic fused silica (SFS) can be well described by a relation Ith equals 1.45 (lambda) 0.43 where Ith is LIDT in J/cm2 and (lambda) is wavelength in nm. At 266 nm, however, LIDTs were smaller than a half of the calculated value from above relation. This difference can be explained by the damage mechanism; at 266 nm, two-photon absorption-induced defects lowered the LIDT same as in the case of KrF-excimer-laser induced defects, whereas at longer wavelength two-photon processed is not occur. LIDTs of fused quartz (FQ) at 532 and 355 nm, and that of a SFS containing about 1000 ppm of Cl and no OH at 355 nm were a little lower than those of the other SFS. This may be related to the absorption of metallic impurities in FQ and dissolved Cl2 molecules in SFS. At 266 nm, on the other hand, LIDTs of FQs were lower than those of most SFSs.