租稅制度的存在與廠商的租稅逃漏問題是兩個不可忽視的經濟現象，然而既存的出口貿易文獻卻忽略這兩種經濟現象對出口貿易政策的影響。有鑑於此，本文設立一個包含公司稅以及逃漏稅的經濟模型，在廠商成本差異化的情況下探討租稅制度與租稅逃漏對最適出口貿易政策造成的影響。文中有幾個重要發現：首先，廠商的產出決策獨立於逃漏稅決策，因此逃漏稅的存在並不會影響市場的均衡以及最適出口貿易政策的制訂。其次，公司稅制會扭曲廠商的產出決策，只要市場需求曲線不要太凹，或是本國廠商成本的變異係數夠低，出口貿易政策與租稅政策間將具有替代性，也就是說，當最適的出口貿易政策為出口課稅（補貼）時，出口稅率（補貼率）將會較傳統文獻為低（高）。最後，在最適出口貿易政策的均衡下，引進公司稅制，或是策略性地增加稅制的扭曲可增進社會的福祉。 The literature on strategic trade policies has neglected the impact of the corporate tax system and tax evasion on these policies. Therefore, in this paper we take these factors into account and explore their effects on strategic export policies with cost heterogeneity. Under our setting, there are several interesting findings: First, the corporate tax evasion problem is not an important factor when the government implements the optimal trade policies. Second, the corporate tax system will distort the domestic firms' output policies, and if either the demand curve is not too concave or the variance of the distribution of unit cost within the domestic industry, is sufficiently low. The export trade policy and tax policy are substitutes, in the sense, that when the optimal export trade policy is an export tax (subsidy), the export tax (subsidy) rate will be higher (lower) than the traditional literature shows. Third, starting from the optimal export trade policies Cournot equilibrium, either strategic ally raising a small corporate tax on the domestic firms or making the tax system more distorted will improve the home country's welfare.