Abstract: Considering V2O5 as a gas-sensing materials,we successfully manufactured 2 dimensional V2O5 film by Sol-Gel method.The gas-sensing reflective spectra in ammonia,alcohol,acetone and butane vapor are experimentally studied.The experiments show that the film has good gas selectivity and monotonicity of the response curve in whole visible spectrum to ammonia.So the film can be used in optical fiber gas sensing head.