This dissertation investigates food safety regulations and international trade of agricultural products dividing into three aspects: the signalling effect from U.S. strict food safety regulations on U.S. vegetable exports, political determinants of sanitary and photosanitary non-tariff barriers, and the impact of trade barriers on employment in developing countries. In chapter 2, we investigate the impact of high U.S. maximum residue limit (MRL) standards on U.S vegetable exports to 102 countries utilizing the hierarchical model. MRL, which is one of non-tariff barriers with respect to food safety, is applied to home and foreign countries at the same time. Thus, firms in countries with higher food safety standards are expected to have a competitive advantage from the ‘signalling effect’. The results show that high MRL standards in the U.S. have a positive impact on U.S. vegetable exports, indicating the ‘signalling effect’ from the strict U.S. domestic MRL standards. The results provide policy makers with insights into how strict food safety regulations of the home country can be considered as a catalyst for increasing competitiveness in international markets. In chapter 3, we examine the political determinants of SPS notifications using a nonlinear threshold model with possible threshold variables (GDP per capita and tariff rate). This article finds no threshold values in both variables of GDP per capita and tariff rate. Our results also show that GDP per capita has a positive relationship with SPS notifications that are one of proxy variables for food quality. That implies the importance of quality competition in agriculture and food sectors. Our finding also represents no significant effect of tariff on SPS notifications. This indicates that a law of constant protection, presenting an inverse relationship between tariff and non-tariff barriers, is not satisfied in the agricultural and food sectors. In chapter 4, we investigate the impact of tariff and SPS barriers on food manufacturers’ skilled and unskilled employment in developing countries utilizing a structural equation model. Results show that both tariff and SPS barriers have a positive effect on unskilled labor employment in developing countries, while trade barriers are not associated with skilled labor employment. This implies that Hecksher-Ohlin theory, presenting labor abundant countries have a comparative advantage in labor-intensive industries such as food, explains well our results since developing countries are abundant in low-skilled labor. We also find that the age of food firm in developing countries is positively related to skilled employment; however, no relationship with unskilled employment. This implies that older food firms change their production process from labor intensive to capital or machine intensive.