The paper incorporated the sociocultural theory into a unit plan of an EFL (English as a foreign language) reading course. The researcher first introduced the definition and relevant studies on the sociocultural theory and L2 (second language) reading, and summarized some interactive studies between the two subjects. Then, the researcher designed a unit plan, which covered several themes of the sociocultural theory, e.g., collaborative scaffolding, self-regulation, and MLE (mediated learning experience). Five successive lesson plans within the unit were then elaborated, with various tasks embedded in each one. All the tasks were designed according to the selected themes, namely, matching game, final word game, and jigsaw activity served as the examples of collaborative scaffolding; tasks like scanning and skimming information in the timeline involved self-regulation; and activities of read-with-songs and read-by-role-play embodied the tenet of MLE. After the five lesson plans, the researcher made the reflection and explained the reasons for the design of the tasks in each lesson plan. Implication for the future studies suggested more experiments be implemented to prove the effectiveness of sociocultural theory in the EFL reading classroom.