Genetics is a branch of biology that studies the laws of inheritance and variation from the level of genes (genomes). Genetics teaching should be compatible with the evolving genetic disciplines and social needs. In view of the continuous development of the genetics knowledge system and the requirements for the training of biological students, our teaching team carried out the curriculum design and implementation of genetics blended course under the principle of constructive alignment. The reform actions include: (1) constructing genetics online resources with genetic analysis as the main line; (2) optimizing the learning objectives according to bloom's educational goals classification; (3) designing learning activities and learning assessments under the principle of constructive alignment; (4) enrich the forms of learning activities, highlighting learning-centered course design and learner interaction, promoting active learning, and improving learning outcomes. The results of the questionnaire survey and exam result analysis suggest that the blended course reform has achieved initial results. The course is fully affirmed by the students and helps to improve learning outcomes, which is worthy of further consolidation and promotion. This paper generally introduces the curriculum design and preliminary practice of genetics blended course, providing new insights and approaches for the continued development of genetics teaching in the new era.