Abstract: CMS male sterile line L9 A and its maintainer line L9 B selected by the research group were used as test materials, and L9 A was used as female parent and 22 excellent inbred lines were used as male parent to prepare hybrid combinations.The differences of morphological characters between male sterile lines and maintainer lines, and the heterosis of 11 agronomic characters and 5 quality characters in F₁ generation were studied and analyzed, in order to provide reference for pepper breeding practice.The results showed that there were significant differences between L9 A and L9 B in plant height, plant width, stamen length and style length, and the heterosis was commonly observed in 22 pepper F₁combinations.Three paternal inbred lines, L59,L90,and L117,could restore the fertility of L9 A,and their F₁ combinations displayed obviously positive heterosis in fruit number per plant, yield per plant, and seed number per fruit.At the same time, it was found that the positive heterosis of F₁ generation was observed just in one or two quality traits.By the analysis of heterosis index, it was showed that the F₁ generations of L9 A had greater heterosis in pepper fruit flesh thickness, plant height, plant width, single fruit weight, soluble sugar content, and soluble protein content.By the correlationship analysis, a very significant positive correlation was presented between yield per plant and fruit number per plant, while no significant correlationship was observed between any two quality traits.In conclusion, in the practice of pepper breeding, the pepper yield in a single plant can be improved by heterosis breeding to increase the fruit number of single plant andsingle fruit weight, while it is difficult in some degree to improve the quality traits of pepper fruit through heterosis breeding.