Abstract： The studies on production, distribution and nutrient return of fine roots (d ＜ 2 mm) in a mixed fir forest at age 27 were carried out in Sanming of Fujian, China. The standing crops of dry matter, N and Pin fine roots of the mixed stand were 5. 381 thm -2, 48. 085 kg hm -2 and 4. 174 kg hm-2, 17.4%, 27.2%and 20.0% higher than those of the pure stand, respectively. The fine root production in the mixed forest was up to 4. 124 t hm-2 a-1, 16.9% higher than that in the pure stand. Fine roots of Chinese fir and the subsoil. Compared with those in the mixed forest, fine roots of Chinese fir in the pure forest had a deeper and Chinese fir in the mixed stand, and Chinese fir in the pure stand, were 1.16, 0.96 and 0.95, respectively. The undergrowth species had higher root turnover rates than their respective tree layers ( 1.46 in the mixed forest and 1.52 in the pure stand). The annual mortality, annual return of N and P of fine roots in the mixed forest amounted to 2.119 t hm-2, 18. 559 kg hm-2 and 1. 565 kg hm-2, 1.21 , 1.23 and 1.14 times as much as that in the pure forest respectively. Bulk density, moisture content, total N and humic C were strongly correlated with fine root density along the soil profile in the two forests, with total N giving the highest coefficients of determination. Fig 1 , Tab 4, Ref 32