This paper aims to evaluate the changes of terms of trade of chemical products of Iran, using fisher index and export and import data of 2011-2018. The results show that although the country's chemical exports have grown positively in recent years, but Iran's terms of trade in these products has been significantly decreasing since 2013. In other words, in order to import a unit of weight from the same basket of chemical products in 2014 (base year), the country has had to export more chemical products in terms of weight every year. This terms of trade situation shows a serious weakness in the country's manufacturing policy and trade strategies. Considering global price growth and the global price level of chemical products can be a proper policy to improve the terms of trade, which means moving toward more complex chemical products with higher technology content. The most important step to do this is moving towards more complex chemical products, or in other words, upgrading in the production chain and move to manufacturing the intermediate and downstream chemical products. To do this, creating the necessary conditions for concluding trade agreements, liberalizing financial markets, attracting foreign direct investment and to push domestic investment to intermediate and downstream chemical industries are important tools for making products complicated.