General characteristics and life span of silkworm moth were investigated amongst 277 gene resources preserved and maintained in Korea. Silkworm varieties were classified according to the commercial characteristics and the viability of tested varieties. There were significant differences among the eight different commercial characteristics of silkworm such as whole larval period, duration of 5th instar, pupal body weight, single cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon yield and longevity, Tropical race showed the longest life span among the other five geographical races, and followed by Japanese, European, Chinese and Korean race in order. In the longevity of each variety, Daizo(sdi) showed the shortest life span with 4.3days, and J037 was the longest as 16.0 days. Average longevity of female was 11.1 days as showed 3.0 days longer than that of male which was 8.2 days. Total average longevity of the whole varieties was 9.7days. In the correlation between the longevity and commercial characteristics, there was a tendency that the commercial characteristics became better when the life span was longer. According to the result of Complete Linkage Cluster Analysis, the genetic resources of 277 silkworm varieties classified into 5 groups such as “Group I”for short life span with low cocoon yielding “Group II”for middle life span with middle cocoon yielding,“Group III”for the shortest life span with low cocoon yielding, “Group IV”for high pupation rate and the highest cocoon yielding with comparatively long life span, and “Group V”for the longest life span with comparatively high cocoon yielding.