Abstract: "A verdict can't base on isolated evidence" is the hidden rule in the practice of criminal justice. Through an empirical study, we find out the following problems in the application of the rule. First, the concept of "isolated evidence" is misused, which makes it difficult to accurately define the connotation of "isolated evidence"; second, over emphasis on the quantity of evidence results in neglect of the quality of evidence and of the examination of the probative power of evidence; the third is the lack the judgement and reasoning of evidence review. In order to correct the defects of the rule, we suggest re-interpreting, understanding and breaking the rule from the following aspects: first, accurately defining the concept of "isolated evidence" and divide the types of isolated evidence; second, to clarifying the subjective conditions and procedural conditions for the determination of isolated evidence; third, seeking for appropriate methods for determining "isolated evidence" through evidence reinforcement and modal evidence supplementation.

Key words: isolated evidence, a verdict can't base on isolated evidence, evaluation of evidence through inner conviction, discretional evidence, quality of evidence