This thesis emphasizes the role of firm heterogeneity in financial factors and their impact on exporting decisions or off-shoring decisions, and apply it to three different issues : the relationship between firms' leverage and export market participation ; the differential impact of uncertainty on exporting decision in risk-averse and risk-taking firms ; and financial characteristics of firms and relocation choice. The first chapter introduces a financial dimension as an additional source of firm heterogeneity to understand export market participation and examines how the impact of leverage on firms' exporting decisions varies depending on financial constraints, using a panel of korean manufacturing firms over the period of 1994-2011. It shows that the financially-constrained and financially-unconstrained firms base their exporting decision on a different set of rules regarding the leverage. Second, most of the existing literature which examines the links between firm heterogeneity and entry into exporting rests on the assumption that firms are risk-neutral. The second chapter relaxes a strict assumption that firms are risk-neutral and intends to introduce firms' different attitudes towards risk as an additional source of firm heterogeneity. In particular, it examines how risk attitude changes the effect of uncertainty on firms' decision to export, considering two aspect s: firm-specific uncertainty and macroeconomic uncertainty. The third chapter pays attention that fdi can fuel international trade in complicated ways. It intends to consider firms' financial constraints and ownership status as an additional source of firm heterogeneity that impact their offshoring decision.