Abstract: ‘Chuanjin 5’is a new ultra-early-maturing seedless citrus cultivar bred by crossing‘Jinqiu Shatangju’as the pollen parent and‘Nanxiang’as the seed parent. This cultivar has medium tree vigor,and can flower and bear fruits in the 2nd year after planting,entering the full fruiting period in the 5th year with a yield of 45 000-60 000 kg · hm^-2. The fruits are oblate,with a single fruit weight of 70-150 g and seedless flesh. The soluble solids content of the flesh is 11%-14%,the total acid content is 0.4%-0.6%,the solid-acid ratio is（18-30）∶1,and the fruits have a sweet and non-astringent taste and are not prone to cracking. In the producing areas of Sichuan and Chongqing,the fruits mature in mid-to-late September,and can ripen as early as late August in the dry-hot valley areas of Yunnan,which is about 30 days earlier than its male parent. The fruits can be stored at room temperature for 15-20 days and for more than 60 days under cold storage at 4-8 ℃. It is highly resistant to canker disease,suitable for cultivation in areas with an annual average temperature of 16-21 ℃ and deep,fertile soil.

Key words: citrus, cross breeding, early-maturing, cultivar