NOVELTY - Boswellia serrata gum resin is extracted using alcohol-demineralized water mixture and filtered to remove insoluble compounds. The pH of extract is adjusted, and extract is concentrated. Demineralized water is added to concentrated extract, to precipitate lower terpenes and non-polar impurities/other gums. The obtained mixture is cooled, and gums are allowed to settle. The solvent is separated from sediment. The extract is diluted, to precipitate boswellic acids with inorganic acid. The precipitate is filtered, washed and dried, to obtain standardized boswellic acids fractions.    USE - Preparation of standardized fractions of boswellic acid used in pharmaceutical composition for treating rheumatism, respiratory diseases and liver disorders and modulating immune systems, and as antiinflammatory, antiarthritic, antiulcerogenic, and antitumor.    ADVANTAGE - The method is economical and environmentally-friendly, enables manufacture of highly-pure standardized fractions of boswellic acid, with high yield, and eliminates use of toxic solvents e.g. hexane, ether, ketone, ester, benzene, toluene and chlorinated hydrocarbons.    DETAILED DESCRIPTION - Boswellia serrata gum resin is extracted several times using alcohol-demineralized water mixture and filtered to remove insoluble compounds. The pH of extract is adjusted to 8-9.5 using aqueous alkaline solution, and then the extract is concentrated to 20-50% of its initial volume. 40-60% Demineralized water is added to the concentrated extract, in order to precipitate lower terpenes and non-polar impurities/other gums. The obtained mixture is cooled to less than 10 degrees C, and the gums are allowed to settle for 15-30 hours. The solvent is separated from the sediment by filtration or decantation or siphoning. The solvent layer is concentrated to 20-50% of its initial volume, and 20-30% demineralized water is added to the remaining gums. The obtained mixture is cooled to less than 10 degrees C, and the gums are allowed to settle for 15-30 hours. The solvent is separated from the sediment by filtration or decantation or siphoning, and ethanol is evaporated. The extract is diluted with demineralized water, to precipitate boswellic acids with inorganic acid having pH of 1-4. The precipitate is filtered and washed with demineralized water till neutral pH, and dried under vacuum, in order to obtain standardized boswellic acids fractions.