Abstract: 1,3- dithiocycloheptane were prepared through the aldehyde with Bunte’s Salts prepared from 1,4-dichlorobutane and sodium thiosulfate. The yield of 1,3- dithiocycloheptane is 63%.The period of reaction is about 14h.The optimum molar ratio of 1,4-dichlorobutane and sodium thiosulfate was 1:1.The structure of 1,3- dithiocycloheptane were characterized by IR,1HNMR, MS. The odour of 1,3- dithiocycloheptane was identified ,the result showed that it’s odour is intense onion and garlic fragrance.. The threshold of1,3- dithiocycloheptane is 0.25×10-6～0.33×10-6 in water and 13.00×10-6～22.00×10-6 in vegetable oil.

Key words: Bunte salts, synthesis, 1,3-dithiocycloheptane, odour