Novel liquid 7-dioctylamino-, 7-(didecylamino)-, 7-(1-butyl-pentyloxy)-, and 7-(1-octylnonyloxy)-4-methylcoumarins were found. They showed melting points in the range of -55.1 to -42.8 degrees C as a metastable liquid phase followed by rearrangement in the range of 1.7 to 20.0 degrees C to form stable liquid phase. The 7-dialkylamino and 7-alkoxy derivatives showed fluorescence maxima at around 440 and 400 nm with fluorescence quantum yields ca. 0.16 and 0.06 in neat form, respectively.