After seed radiated by γ-rays, diagrams of peroxidase isozymes in barley seedlings were changed, and chromosomal aberration in root tip cell were produced. The dose-effects on peroxidase isozymes number and cell rate with chromosomal aberration were fitted by linear regression equations Y=Ax+B. The results showed that the radiosensitivity of naked barley was higher than that of hulled barley, and two row-lower than four- and six- row.