本文研究了立地分类的理论、系统和方法。提出自然条件的宏观分异绝对性,和微观分异相对性;树种资源优势的相对性和绝对性;肥力的生态相对性和生态因子的综合作用规律是立地分类的基本理论依据。指出数值分类方法尤为适合解决立地分类问题,并拟定了新的立地分类系统。 This paper studies the theory, system and method of site classification. The macroscopical differentiation absoluteness and microscopic differentiation relativity of natural conditions were proposed. The relativity and absoluteness of tree species resources superiority. The law of ecological relativity of fertility and the comprehensive effect of ecological factors were the basic theoretical basis of site classification. It is pointed out that the numerical classification method is especially suitable for solving the problem of site classification and has proposed a new site classification system.