A new detection system consisted of a flame ionization detector(FID) and a sulfur chemiluminescence detector(SCD) was developed for sensitive and interference free determination of total sulfur in natural gas by non-separation gas chromatography. In this system, sulfur containing compounds and hydrocarbons were firstly burned in the FID using oxygen rich flame and converted to SO_2, CO_2 and H_2O, respectively. The products from FID were transported into the SCD with hydrogen rich atmosphere wherein only SO_2 could be reduced to SO and reacted with O_3 to produce characteristic chemiluminescence. Therefore, the chemiluminescence of CO found in conventional SCD were eliminated because CO_2 could not be reduced to CO under these conditions. The experimental parameters were systematically investigated. Limit of detection obtained by the proposed system is better than 0.5 mmol/mol for total sulfur and superior to those previously reported. The proposed method not only retains the advantages of the conventional SCD but also provides several unique advantages including no hydrocarbon interference, better stability, and easier calculation. The utility of this technique was demonstrated by the determination of total sulfur in real samples and two certified reference materials(GBW 06332 and GBW(E) 061320). A new detection system consisted of a flame ionization detector (FID) and a sulfur chemiluminescence detector (SCD) was developed for sensitive and interference free determination of total sulfur in natural gas by non-separation gas chromatography. hydrocarbons were initially burned in the FID using oxygen rich flame and converted to SO_2, CO_2 and H_2O, respectively. The products from FID were transported into the SCD with hydrogen rich atmosphere where only SO_2 could be reduced to SO and reacted with O_3 to produce characteristic Therefore, the chemiluminescence of CO found in conventional SCD was eliminated because CO_2 could not be reduced to CO under these conditions. Limit of detection obtained by the proposed system is better than 0.5 mmol / mol for total sulfur and superior to those previously reported. The proposed method not only retains the advantage s of the conventional SCD but also provides several unique advantages including no hydrocarbon interference, better stability, and easier calculation. The utility of this technique was demonstrated by the determination of total sulfur in real samples and two certified reference materials (GBW 06332 and GBW ( E) 061320).