Abstract: ‘Summer Power’is a new Iris ensata var. hortensis cultivar derived from the cross breeding of female parent I. ensata and male parent I. ensata var. hortensis‘Renkyu-shiro’. The plant height is about 65.8 cm. Color of the standards of‘Summer Power’is light blue-purple（RHS 91D）with blue-violet（N87B）edge and apex. The fall is blue-violet（Ｎ87A）with dark blue-purple（90B）flower veins and light blue-purple（91C）spots. The style arms are white（N155D）with blue-violet（N87D）margins and apexes. It has a slight floral fragrance. The florescence is from late May to early June in Hangzhou region. The flowering period of a single plant is about seven to ten days. It has the characteristics of novel flower color，large flower size and strong stress resistance. It is suitable for open field cultivation from North China to the Yangtze River Basin.

Key words: Iris ensata var. hortensis, cultivar