<p>This study intends to apply scaffolding theory to the teaching of English subjunctive mood in senior high schools. After reviewing the researches about scaffolding theory and some studies related to English grammar teaching, the author puts forward a real lesson plan for subjunctive mood teaching, which includes the analysis of teaching material, teaching aims, teaching key point and difficult points, teaching method and the most important, teaching procedures. During the teaching procedures, the author tries to analyze every step, namely, lead-in, presentation and observation, discovery, practice, production, summary and homework, and after-class reflection, from the perspective of scaffoldings the teacher has given to students. The final finding shows that scaffolding can stimulate students’ interest in learning, and improve their ability of independent and cooperative learning. On the whole, the practice of applying scaffolding theory can be encouraged in English grammar teaching.</p>