The change characteristics of soil and soil microbial biomass contents of the natural secondary forests could significantly affect the soil organic carbon (C_soil), total nitrogen (N_soil), total phosphorus (P_soil), soil microbial biomass carbon (C_mic), microbial biomass nitrogen (N_mic), microbial biomass phosphorus (P_mic) contents, and their stoichiometry. To gain insights into the change characteristics of soil and soil microbial biomass contents and their stoichiometry along different successional stages of natural secondary forest, four forest types were selected in Miyaluo forest area of western Sichuan, China, which compose of three natural secondary forests (SF60, SF70 and SF80 from clear-logging area during the 1960s, 1970s and 1980s, respectively) and one Abies faxoniana primary forest (PF, 160 years old). C_soil, N_soil and P_soil, C_mic, N_mic and P_mic in 0-20 cm soil were measured. The results showed that contents of C_soil and N_mic marginally significantly decreased, whereas the contents of N_soil and P_soil, C_mic and P_mic increased initially but decreased over time late in the course of restorative succession of natural secondary forests. The contents of C_soil, N_soil, P_soil, C_mic, N_mic, and P_mic in the three natural secondary forests were lower than those in the PF, while the contents of C_soil, N_soil and soil microbial biomass had no significant changes between SF80 and SF70. The content of P_soil was significantly higher in SF70 than that in SF80. The soil C:N:P stoichiometry ratio was dominated by the synergy effect interaction of N_soil and P_soil contents. There was no obvious difference among forests of different successional stages for soil microbial nitrogen carbon quotient (qMBC) and phosphorus quotient (qMBP), but did exist for soil microbial nitrogen quotient (qMBN). qMBN was significantly greater in SF60 than that in the other two successional stages and PF. C_imb:N_imb ratio of the stoichiometric imbalances showed first decreased and then increased; C_imb:P_imb and N_imb:P_imb ratio of the stoichiometric imbalances showed a slightly and significantly gradual reduction, respectively. Redundancy analysis showed that soil microbial quotient (qMB) was significantly correlated with N_imb:P_imb and C_mic:N_mic ratio. N_imb:P_imb ratio revealed 62.6% of the variations in qMB, which implied that changes of qMB values were effected by the contents of N_soil, P_soil and their active components (N_mic and P_mic). Furthermore, our results revealed that nitrogen and phosphorus contribution could be an optimal strategy to meet the microbial stoichiometric demands and enhance nutrient availability for natural secondary forest at the early-successional stages (<60 a) in high-altitude sub-alpine forest ecosystems.