A comparison has been made for the quenching effect of three classes of organic solvents on the porous silicon photoluminescence, including hydrocarbons, solvents containing oxygen and nitrogen. Among them organoamines possess the strongest quenching effect. The experiments show that the solvent molecules interact synergistically with porous silicon and the main pathways include the surface hydrophobic interaction, dipole-dipole interaction and hole trapping, the later being the dominant pathway in quenching of porous silicon photoluminescence.