Understanding how power is communicated by instructors and students is important to student motivation and learning. To examine how power is communicated online by instructors and how receptive (or not) students are to this, I examined four online graduate seminars using two analytical tools: community of inquiry (COI) theory and McCroskey and Richmond's (1983) five bases of power framework. To communicate power, instructors drew from expert, referent, and legitimate power bases to cultivate teaching and social presence and to help students acquire cognitive presence. Direct instruction, feedback, and tools such as the syllabus and discussion board helped instructors communicate power.