Cycling of nutrients, such as Carbon (C) and Nitrogen (N), is one of the most important soil functions and is strongly related to the composition of the soil microbial community. However, soil is increasingly under environmental pressures that threaten its ecological functions and sustainability. To maintain soil functional sustainability, it is important to understand how soil withstands environmental stresses (subsequently referred to as resistance) and recovers from stresses (subsequently referred to as resilience). This study focused on the resistance and resilience of C and N processes and the underpinning microbial communities to a persistent Cu stress or a transient heat stress. The main advances and novel findings of this thesis are: (1) C mineralization is more resistant and resilient than ammonia oxidation and denitrification, and thus the combination of C and N processes are more informative than measuring a single process to interpret the overall resistance and resilience; (2) microbial composition and microbial physiological evolution play important roles in affecting resistance and resilience; (3) soil physico-chemical properties (e.g. organic matter, soil water and soil pH) are critically important in conferring resistance and resilience. The outcome of this study advances the understanding of the mechanisms of soil resistance and resilience of C and N cycling to environmental changes. The results generated here are an essential step for improving soil sustainability and promoting agricultural productivity under future environmental challenges.