To use color Doppler ultrasonography to evaluate the morphology and vascularity of calcific tendonitis and to predict the formative and resorptive phases of the calcification. Ninety-four patients with shoulder calcification on plain radiographs were enrolled in this study. Ultrasonography of the shoulder was focused on the rotator cuff. Color Doppler ultrasonography was applied in the calcific region. Patient symptoms were graded as painless, mild, moderate, and severe. The calcific plaques were classified as arc-shaped, fragmented or punctate, nodular, and cystic types. Color Doppler ultrasonographic signals were graded 0 to 3. The formative and resorptive phases of calcification were categorized by patient symptoms; acute onset of moderate or severe pain indicated the resorptive phase. The calcific plaques appeared arc shaped in 59 patients (20 painless, 19 mild, and 20 moderate), fragmented or punctate in 27 (2 painless, 3 mild, 20 moderate, and 2 severe), nodular in 6 (1 moderate and 5 severe), and cystic in 2 (severe). There was a significant difference between the morphology of the calcific plaques and clinical symptoms (P < .01). On color Doppler ultrasonography, grade 0 signals were found in 28 patients (22 painless and 6 with mild pain); grade 1 in 18 (16 mild and 2 severe); grade 2 in 41 (all moderate); and grade 3 in 7 (all severe). The correspondence between color Doppler ultrasonographic findings and clinical symptoms was excellent (P < .01). High-resolution ultrasonography with color Doppler imaging could differentiate the formative and resorptive phases of the calcification and could be used as a follow-up modality in calcific tendonitis of the shoulder.