The biological fertility is in central and core position of soil fertility. Soil of Phyllostachys edulis forest in core scenic spot within the south Sichuan bamboo sea was taken as the object and soil biological factors were selected as the evaluation indexes. The spatial heterogeneity of the factors and the whole level of soil respiration rate were analyzed through both geo-statistical and traditional statistical methods. On this basis, an index model of soil biological fertility was carried out with principal component analysis and fuzzy mathematics to evaluate the quality of soil biological fertility in this area. The results showed that the variability of all biological fertility indexes ranged from moderate to intense, and the ranges were 1 326–2 219 m. Each index showed a strong spatial correlation in its range. The mean rate of soil respiration in study area being 3.38 μmol/(m²s) reflected that the interference of this forest land was serious. In the five divided biological fertility grades, the third and forth have the highest percentage in size, covering 65.01% of the whole area, while both the first and fifth less than 10%. In general, the quality of soil biological fertility in the study area was in middle level.