Abstract: Based on the inputoutput panel data of 27 coastal counties in Zhejiang Province from 2005 to 2018, combined with super-efficiency SBM model and projection pursuit model, we examined the spatialtemporal variations of ecological efficiency, and the superposition characteristics of inputoutput and ecological efficiency, and proposed the strategies to optimize ecological efficiency in coastal Zhejiang Province. The results showed that: (1) The ecological efficiency of coastal counties could be divided into two stages: stable growth period and bumpy decline period. (2) The ecological efficiency of coastal counties in northern Zhejiang was higher than that of southernZhejiang. The ecological efficiency of coastal counties in north Zhejiang and south Zhejiang had asymmetry and spatial variation. (3) The ecological efficiency of different levels in coastal counties was characterized by mutual transformation. The high ecological efficiency changed from “large aggregation” to “small dispersion” pattern. The relatively low ecological efficiency and low ecological efficiency evolved from “large dispersion” to “small aggregation”, with the characteristics of “constant weak”. (4) The change of resource input and economic benefit in coastal counties had the same high and low characteristics. Environmental pollution had the opposite characteristic with resource input and economic benefit. (5) The superposition types of input-output elements and ecoefficiency grades were diverse and complex. The counties with high input and high economic benefit were basically stable. Medium input counties were distributed in the periphery of high input counties. Low input counties were mainly concentrated in the coastal areas of southern Zhejiang.

Key words: ecological efficiency, super efficiency SBM model, projection pursuit model.