[Purposes] This paper aims to study the effect of z-index in journal evaluation. [Methods] Taking the information science and library journals indexed in Social Science Citation Index as examples, we calculated the total number of published data, total citation frequency, average citation frequency, η, h-index, p-index, and z-index, and analyzed the effect of z-index on the evaluation of journal influence in an empirical way. [Findings] The z-index is more suitable for comprehensive evaluation of the quality, quantity, and cited distribution of journal academic influence than the h-index and p-index. [Conclusions] The application of z-index in the evaluation of journals is helpful to motivate journals to publish high-level papers, and z-index has high sensitivity and diversity. However, z-index also has disadvantage, such as being unable to distinguish the influence of citation literature.