NOVELTY - 5( alpha )-Chloro-hydroxy-androsta-6( beta )-3( beta ),17( beta )-diol diacetate (V) is reacted with 1,3-dibromo-5,5-dimethylhydantoin, anhydrous sodium carbonate, benzoyl peroxide, iodine and benzene, and refluxed. Then, aqueous sodium thiosulfate solution is added, stirred and solid-liquid separated. Potassium hydroxide is added to organic layer, refluxed, and cooled to obtain 5( alpha )-chloro-androsta-6( beta ),19-epoxy-3( beta ),17( beta )-diol (VI). Obtained diol is reacted with acetone, oxidant and aqueous sodium bisulfate to obtain 5( alpha )-chloro-androsta-6( beta ),19-epoxy-3,17-dione (VII).    USE - Preparation of 5- alpha -chloro-androstane-6- beta ,19-epoxy-3,17-diketone (claimed) used for preparing family planning medicine.    ADVANTAGE - The method efficiently and economically provides of 5- alpha -chloro-androstane-6- beta ,19-epoxy-3,17-diketone with high yield without causing pollution to environment.    DETAILED DESCRIPTION - 4-Dehydroepiandrosterone of formula (I) is added to a reaction container, then acetic anhydride and p-toluenesulfonic acid are added and reacted to obtain androsta-3,5-dien-17-ol-3( beta )-acetate of formula (II). The obtained compound is mixed with methanol and sodium borohydride, and reduced to obtain androsta-5-ene-3( beta ),17( beta )-diol of formula (III). The obtained compound is reacted with toluene, acetic anhydride and pyridine to obtain androsta-5-ene-3( beta ),17( beta )-diol diacetate of formula (IV). The obtained diacetate is reacted with acetone and water, then trichloroisocyanuric acid/acetone is dripped to reaction mixture, and reacted to obtain 5( alpha )-chloro-hydroxy-androsta-6( beta )-3( beta ),17( beta )-diol diacetate of formula (V). The obtained compound is reacted with 1,3-dibromo-5,5-dimethylhydantoin, anhydrous sodium carbonate, benzoyl peroxide, iodine and benzene, and refluxed. Then, aqueous sodium thiosulfate solution is added, stirred, stratified, and solid-liquid separated. Potassium hydroxide is added to organic layer, refluxed using ethanol, cooled to room temperature, and pH value is adjusted to neutral, to obtain 5( alpha )-chloro-androsta-6( beta ),19-epoxy-3( beta ),17( beta )-diol of formula (VI). The obtained diol is reacted with acetone, oxidant and aqueous sodium bisulfate to obtain 5( alpha )-chloro-androsta-6( beta ),19-epoxy-3,17-dione of formula (VII). An INDEPENDENT CLAIM is included for 5- alpha -chloro-androstane-6- beta ,19-epoxy-3,17-diketone.