Studies on secondary production can lead to a better understanding of the functions of the macrobenthic ecosystem. To determine the secondary production and production-to-biomass ratio (P/B) of the macrobenthic community in the northern East China Sea, we conducted annual investigations in the northern East China Sea from 2012 to 2016. In this study, the secondary production and P/B values of the macrobenthic community in the northern East China Sea, China, were described and analysed using PCA and Spearman rank correlation analysis. A total of 61 species were collected and identified, and the results showed that Polychaeta was the most speciose group. The polychaete Sternaspis scutata and holothurian Acaudina molpadioides were found to be the most important contributors to the total abundance and total biomass across all sampling areas and years. The Spearman rank correlation analysis indicated that community abundance was positively correlated with depth but negatively correlated with dissolved oxygen (DO) and suspended solids (SS). The P/B was much lower than that found in previous reports from this area, mainly due to the collection of large individuals of A. molpadioides from Sanmen Bay. The low P/B value also indicated that more effort and time are needed to rehabilitate the benthic marine ecosystem in this area.