法律推理中已认定的案件事实是小前提。以论证的形式给当事人和社会公众一个说服力比较强的判决理由。这是法律推理的最终目标。本文从相关概念出发,说明了小前提的构建过程是将案件事实上升到法律事实。这个过程中凝聚着法官的心血。小前提的建构受到证据和法官的自由裁量权因素的影响。 The facts of the case that have been found in legal reasoning are small prerequisites. In the form of argument to the parties and the public a more convincing reason for the verdict. This is the ultimate goal of legal reasoning. Starting from the related concepts, this paper shows that the construction of small premises is to raise the facts of the case to legal fact. In the process, there is a concentration of judges. The construction of small premises is influenced by the evidence and by the judges’ discretion.