Human practice is related to the relationship between man and nature and determines the degree of understanding of their relationship. From the viewpoint of historical materialism, nature is the nature that has been experienced, realized, and practiced. The relationship between man and nature and its understanding has the logic of generation and evolution. Global ecological problems and development problems are the realistic foundation and inevitable requirement of building a community of human and natural life. "Man and nature are the community of life" emphasizes the dialectical unity between man and nature. The "life community of human and nature", which emphasizes the inner identity between human and nature, is an upright innovation of Marx's view of nature and an accurate summary of ecological civilization construction.