Semi-automatic cryogenic-preconcentrator is constructed with time controlling function in preconcentration and desorption stage. GC-FPD and cryogenic-preconcentrator were to analyze gaseous sulfur compounds (hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide) in ppbv level. The objective of this study was to offer reliable methods for sulfur gas analysis in all procedures (keeping, concentration, desorption, and detection). The cryo-concentrator was able to concentrate 4 L gas sample of 40 % relative humidity. The recovery rate of the system was in the range of 92~100 % at 30 seconds of pre-heating time, and method detection limits were shown up 0.16~0.20 ng which is able to quantify 1 ppbv level with 0.5 L gas sample. The storage time of 5 ppbv sample in polyethylene bag led to serious loss (e.g; H₂S: loss of 30% after storage 3 days). It was estimated that the analytical bias was affected more sensitively by storage time after sampling than by cryo-injection procedures in the analysis of hydrogen sulfide and methanethiol.