Abstract:The economic and field performance of six Bombyx mori Linnaeus bivoltine strains were evaluated, namely ICIPE I, Chun-Lei X ZhengZhu (C X Z), QuiFeng X BaiYu (Q X B), Quingsong X Haoyoe (Q X H), Suju X Minghu (S X M) and 75xin X 7532 (75xin). Performance was based on larval, cocoon, pupa and shell weights, relationship of food consumption to larval weight, cocoon weight and shell weight. ICIPE I recorded the shortest larval development period in Location 1 (S1) during the short rains (SR) (26.53 + 5.05 days) and it was significantly shorter compared to that of the` other strains. It also had the highest cocoon shell weight (CSW) in location 1 (S1) and location 2 S2), 0.38 and 0.36gms respectively. ICIPE I and C X Z strains gave better performance for the parameters evaluated and are most suitable for the Kenyan conditions.