An eco-industrial park or estate is a community of manufacturing and service businesses located together on a common property. The goal of EIP is to create a win-win harmonious development aspect of economic development and environmental protection. This paper emphasizes that the external effect of an EIP is its main characteristic of technoeconomic evaluation for eco-industrial park project. From the view of the property rights, the EIP's product is typically public-private. The government should take some measures for the quantitative analysis on ecological positive externalities of the enterprises in EIP, and also should adopt Coase 's Theorem, which supports that the market transaction is the best way to deal with positive externalities (external economics or diseconomics), or Pigou 's Theorem, which holds that the government anti-positive externalities programs are the best way to cope with positive externalities, to internalize the EIP's external effects, which is also a fundamental tool to encourage investors to actively invest in EIP projects.Furthermore, this paper thinks that the EIP' s income should be equal to the income of staple products of the private property and that of its by-products of the public property. According to this principle, this paper has put forward three major indicators, net present value (NPV), internal rate of return (IRR), and investment repayment period (IRP), which are also extensively used indicators in ordinary project techno-economic evaluation model to evaluate EIP technoeconomic effects. Theoretically, the indicators not only can be used in EIP project evaluation, but also can provide a quantitative measure tool for the government to support EIP's construction to the maximum. In the end, a case is analyzed.