Abstract: Characters variation of a special dwarf mutant CHA1,selected from the induced generation derived from rice cultivar Tehuazhan after space treatment carried by the high space balloon,were studied.The results showed that: Compared with its original Tehuazhan,the main agronomic and economic characters of CHA-1 showed strong variation.The plant height was decreased obviously.The grains mass per plant,panicle length,per panicle spikelets,filled grains per panicle,seed setting ratio,1000-grain mass,grain width and the density of growing grains were occurred negative variation.But the positive variation were found in the characters of panicle number and grain length-width rate.The flowering habit of CHA-1 was normal,but its stigma exsertion rate increased slightly while the pollen fertility and the vigour of pollen decreased compared with its original.The pollens size of the mutant appeared three types: large,middle,and small.CHA-1 was a special dwarf mutant with high apparent grain quality.