This study aims to explore the path model of preschoolers’ family educational environment, parental efficacy, and passion (obsessive passion and harmonious passion) in learning English. The participants in this study were 515 preschoolers’ parents in Taiwan. This study used a survey method that included three instruments developed by the researchers Inventory of Preschoolers’ Family Educational Environment in Learning English, Inventory of Preschoolers’ Parental Efficacy in Learning English, and Inventory of Preschoolers’ Passion in Learning English. This study found that (1) the preschoolers had good family educational environment, parental efficacy, and passion in learning English; (2) Structural Equation Modeling (SEM) found that the interaction between preschoolers’ parental efficacy and family educational environment had effects on obsessive passion via parental efficacy. Moreover, the interaction of preschoolers’ family educational environment and parental efficacy had effects on harmonious passion via family educational environment, and preschoolers’ obsessive passion had effects on their harmonious passion.