Abstract: In order to test the feasibility of the fan test design used in detecting crop density, and determine the optimum planting density of a new faba bean variety ‘Tongcanxian No.8’ in chongqing,the fan test design was be used in the two year repeated test. The results showed that the fan test design in application of detecting faba bean density was feasible. The optimum planting density rage of ‘Tongcanxian No.8’ was 86805-106110 plants per hectare. While the density was 93615 plants per hectare, yield of faba bean reached the highest level.