Oven 350 degrees. 10 inch cake pan.
Rinse blueberries; drain well. Combine dry cake mix, sour cream, eggs; blend at low speed until moist. Beat 2 minutes at medium speed; scrape bowl often. Fold in drained berries. Pour into generously greased, lightly floured 10 inch Bundt or tube pan.
Bake at 350 degrees for 35-45 minutes. Until toothpick inserted in center comes out clean. Cool 15 minutes; remove from pan. Serve warm or cool with powdered sugar or whipped cream.