Purpose: Applying SSCI journals of library and information science(LIS) as the research sample, we explore the feasibility of measuring academic journals' yearly social impact by using altmetric indicators.Design/methodology/approach: Using a sample of 66 SSCI journals in LIS published in 2013, statistics regarding journal mentions in social media and other online tools were retrieved from Altmetric.com and meanwhile citation data was also collected from JCR and Scopus. Based on the method of principal component analysis, data was analyzed for associations between the altmetric and traditional metrics to demonstrate the effect of altmetric indicators on measuring academic journals' yearly impact.Findings: The Spearman's rank correlation test results show that altmetric indicators and traditional citation counts were significantly correlated, indicating that altmetrics can be used to measure a journal's yearly social impact.Research limitations: The time frame of data collected from Altmetric.com may not be consistent with that of JCR and Scopus citation data.Practical implications: A new method is provided based on altmetrics for evaluating the social impact of academic journals, which can be applied to design new indicators of short-term journal impact.Originality value: In this paper, we have established a method for evaluating the social impact of academic journals based on altmetric indictors. Altmetrics can be complementary to traditional citation metrics in assessing a journal's impact within a year or even in a shorter period of time.