Abstract: Experiments were conducted at Castanea henryi cv. youzhen stand in Qingyuan, Zhejiang province. Polygonatum cyrtonema wasinterplanted in September of 2013 at C. henryi cv. youzhen stand. Determinations on fine roots were implemented by stratified sampling in Novemberof 2015, taking pure C. henryi cv. youzhen stand as control. The results showed that under interplanting condition, vertical distribution of fine roots ofC. henryi cv. youzhen concentrated in depth of 0.26m, 0.06m upper than that of the control. Horizontal distribution of fine roots under interplantingmodel concentrated 1.54m away from the trunk, 0.48m farther than that of the control. The experiments resulted that interplanting had positive effecton quantity and distribution of fine root of C. henryi cv. youzhen, but negative one on water absorption of fine roots.