Biological characteristics of Yuanboluo walnut which grow at an altitude of 2 500 m were observed in Yangbi in 2009.The results showed that phenological period of Yuanboluo walnut,compared with Yangbi walnut late ten days or so,was good at high altitude of cooler regions cultivation.Drupe round sphere,kind of shell groove was shallow and take benevolence was easy,the color of benevolence was yellow with purple stripe.Shell thickness was 1.12 mm.Grainweight was 7.4 g,kernel ratio was 49.44%.The taste was delicious and sweet,not acerbity.