For identification and determination of 1, 2-epithioalkanes (EPA), total and thiirane sulfur of them were determined. Investigations by GLC, TLC, UV, IR, NMR and GC-MS of EPA were also carried out for the same purpose. The samples employed were 1, 2-epithio derivatives of octane, decane, dodecane, tetradecane, hexadecane and octadecane.The results of GLC with Silicone DC 430 columns were in fair agreement with the data of total sulful content. 1, 2-Epithiohexadecane and 1, 2-epithiooctadecane, however, were degraded during GLC. For such compounds, TLC with silica gel G and petroleum ether was preferable. Determination methed of thiirane sulfur with iodine-acetic acid solution gave unsatisfactory results. Molecular extinction coefficients of EPA were 40.143.2 at λmax 261262 nm in heptane solution. The IR spectra of EPA and 10, 11-epithioundecanoic acid showed four characteristic bands near 681, 646, 622, and 604 cm-1. By the application of these bands, the concentration of EPA in CCl4 solution was able to be determined, even if small amount of α-olefins or 1-thiols was present. The peaks of the protons of methylene and methyne of thiirane ring appeared at 7.75 τ (quartet) and 7.25τ (quintet) in CCl4 solution, respectively. In the mass spectrum of 1, 2-epithiodecane, parent peak did not exist, but M-32 peak due to elimination of sulfur from the compound appeared Base peak was a peak at m/e 41 due to C3H5+.From the above results, following methods are suitable for the identification and determination of EPA : Combination of GLC and IR for the identification ; combination of GLC and total sulfur content for the determination. For the compounds degraded during GLC, following methods are recomended : Combination of TLC and IR for the identification ; combination of IR and total sulfur content for the determination.