This study investigates a teacher"s practice regarding how Dynamic Assessment (Dixon-Krauss, 1996) is realized in his evaluative activities in a language classroom. First of all, the study pinpoints eight properties of dynamic assessment, and operationally defines and classifies the teacher"s evaluative activities into 6 categories: prior knowledge check, assignment review, task comprehension check, task customization, instance quiz, and achievement check. Furthermore, the study examines how the teacher"s evaluative activities are worked out for a small group of children who are learning their heritage language (Korean). The effectiveness and potentiality of dynamic assessment for a language classroom organized by special purposes are also discussed.