Eco-innovation is the main driver of realizing the coordinated development of resource, environmental and economic systems. This paper measures regional eco-innovation efficiency (EIE) by using the Super-Slack Based Measure (SBM) model with undesirable outputs and distinguishes different agglomeration patterns based on Chinese data of 21 manufacturing sub-industries of 30 provinces. In particular, from the perspective of the dynamic evolution of manufacturing agglomeration, the nonlinear effects of specialized and diversified agglomeration on EIE are investigated based on panel threshold regre...