Abstract: ‘Ruizhu’is a new super-early maturing cultivar of northern highbush blueberry selected from the inbred progeny of‘Amblue’. This cultivar exhibits a dense fruit cluster and large individual fruit，with an average weight of 2.09 g and the largest recorded at 2.37 g. The berry is oblate，with a fruit shape index of 0.75. It displays a thick fruit powder and bright blue. The pedicel scar is small，with no tearing observed during harvesting. The fruit contains 15.94% soluble solids，11.85% soluble sugars，0.48% titratable acids，1.86 mg · g^-1 FW anthocyanins，and 122.6 μg · g^-1 FW vitamin C. The fruit is firm in texture and has an excellent flavor with well-balanced sweetness and acidity. It is suitable for cultivation in the Changbai Mountain production area，the Liaodong Peninsula production area，and the Jiaodong Peninsula production area，with a yield of 10 750 kg · hm^-2.

Key words: blueberry, fresh, super-early maturing, cultivar