[Objective] The input of exogenous active carbon (C) substrate strongly affects the growth of soil microorganisms. However, so far little knowledge is available about dynamic responses of soil microorganisms (bacteria and fungi) to the input of exogenous active carbon substrate and functional traits of the microorganisms in utilizing the substrate and their relationships with community structure of the microorganisms.[Method] Hence, an experiment was carried out using ¹³C-glucose as substrate in Ultisol for incubation of soil microorganisms (bacteria and fungi), which were sampled periodically for analysis with the aid of DNA-based stable isotope probing and high-throughput pyrosequencing techniques to explore dynamic traits of the microorganisms utilizing the carbon of glucose relative to species.[Result] It was found that in utilizing the substrate, the bacterial and fungal communities followed the r/K selection strategy in evolution from bacteria to fungi. Among the bacterial community, copiotrophic bacteria, like Proteobacteria and Actinobacteria, were higher than oligotrophic phyla, like Acidobacteria and Chloroflexi, in activated substrate utilization capacity. Different from bacteria in utilization of substrates, fungi, like Ascomycota and Basidiomycota, were low in selectivity and able to utilize both labile C and native soil organic matter.[Conclusion] Hence, bacteria retain their intrinsic life-history strategies controlled by their copiotrophic or oligotrophic natures, regardless of increase in C availability. Fungi can utilize a wide range of substrates and labile C input can induce copiotrophic Ascomycota to utilize heterogeneous recalcitrant C, thus accelerating decomposition of native soil C.