The callus forming ability and regenerating ability of the calli derived from mature and immature embryos of 132 barley varieties were examined. These materials were taken from a world-wide collection preserved at the Barley Germplasm Center of Okayama University. The callus forming ability varied widely according to genotype in both mature and immature embryos, but the varieties collected from Ethiopia showed low callus forming ability. Calli derived from mature embryos generally did not regenerate shoots, except for three Japanese varieties. The frequency of shoot regeneration from the calli derived from immature embryos was somewhat higher than that from those derived from mature embryos. Many of the Korean and Japanese varieties had a high shoot regenerating ability. However, few of the varieties from Ethiopia and Southwest Asia had a high shoot regenerating ability. No correlation was observed btween root regenerating ability and shoot regenerating ability of the varieties. No correlation was observed between callus proliferation and root regenerating ability between calli derived from mature and immature embryos. We could not find any difference in the shoot regenerating ability btween the two-rowed and six-rowed genotypes.