Abstract: In this paper, Head-Space Gas Chromatography is used to determine micro organo-fluorides in wastewater. We designed an equilibrium bottle and inspected the influences of salt effect, equilibrium time and equilibrium temperature on the result. Minimum detectable concentration for octafluorobutylene is 0.01 ppm. Qualitative determination of organo-fluorides in wastewater was performed with GC/MS.