Four cases of hereditary cerebellar ata-xia are reported.Two of them are brothers

the other two are sister and brother.In thecourse of three successive generations

thefamily members suffering from this diseasein the first and second family are 8 and 4respectively.All of the four patients repor-ted exhibited obvious cerebellar symptomsand signs

of whom two showed pyramidaltract signs and disturbance of deep sensa-tions.The differential diagnosis of otherkind of cerebellar diseases and familial he-reditary diseases are discussed.An extract of the mycelium of Gano-derma capsense（Lloyd）Teng was given tothe four patients intramuscularly at 1 gm./day.All showed some degree of beneficialeffect.Up to early 1980

they had beenfollowed up for 2-4.5 years.The youngestone with the shortest course of disease andless symptoms and signs can work as muchas a healthy person now.The second pati-ent’s long term effect is not so good as thefirst

yet he can undertake some light work.The long term effect in the remaining twopatients with very serious condition beforetreatment was not ideal.