Abstract:In order to obtain long fiber cotton variety which would be adaptable to the ecologicalconditions of Yellow River Region,the mutation induction of Egypt cotton variety,Ash-mouni,was carried out by γ-ray of 279 Gy in 1985.In M1 generation, serious radiation dam-age was shown in seed-lings,the death percentage of seedling was 63.3%,Two plants withearly maturity were selected and their seeds were planted individually in 1986.The complexsegregation appeared in M2 generation,The selection and domestication were carried out forseveral years and four stable mutant lines which included early maturity,dwarf plant,com-pact pattern,stranger bollbearing ability as well as upland cotton characters were obtained in1991.The fiber length of these lines reached 33～35mm,and the mutants were adaptable toecological condition in Shandong Province,The mutant line,90197-1,whose growing periodand plant height shorter than those of upland cotton cultivar, Zhong-mian No,12,has com-pact plant pattern,high bollbearing ability and ginning out turn of about 40%,Further yieldtest is required for these lines,The hereditary variability of the progeny in mutated Egyptcotton variety,preliminary cytological observation and the analysis of isoenzyme in mutantsare also discussed.