Four new 7-alkoxy-4-methyl coumarin dyes and their absorption spectra, fluorescence spectra and lasing properties are studied. In comparison with the fluorescence peak of coumarin dye 4MU, those of the new coumarins shifted about 60 nm to the short wavelength side. These four new dyes give laser emission in the UV region. The laser tunable range and energy conversion efficiency have been determined. Using time-resolved techniques we have observed their kinetic fluorescence and determined the relevant fluorescence life-time.