Although the Chinese constitution includes the notion of socialist rule of law, it is generally assumed that this is not a justiciable principle that courts can apply in practice. The meaning of the principle is determined in authoritative documents of the Chinese Communist Party. Based on newly available court decisions, the paper explores in what instances Chinese courts directly apply the socialist rule-of-law principle, its various elements and other related ideological concepts. The paper argues that courts use ideological concepts in the reasoning parts of judgments either in a supplementary or educational function that lends their decisions legitimacy beyond the law. Further, ideological concepts are used like constitutional principles to give meaning to indeterminate general legal terms. Ideological concepts are applied to support particularly broad or narrow interpretations of general legal terms in order to strengthen the protection of weak parties.