Soil microorganisms play an important role in soil carbon and nitrogen recycling. It is, therefore, necessary to study responses of soil microorganisms to warming for better understanding soil biological processes under global warming. The technique of open-top chambers (OTC) was used in an experiment to explore responses to warming ( 1.1~1.9℃) of soil enzymes in activity and soil microbes in biomass, community structure and respiration in the soil of the tundra ecosystem on the Changbai Mountains. OTCs were established in June, 2010 and kept the temperature inside 1.1 to 1.9 ℃ higher than the air temperature around for three growing seasons consecutively. Results show that warming did not affect much the activities of soil sucrase (0.34 and 0.26 mg g^-1 72 h^-1) or cellulase (58.1 and 45.9 mg g^-1 24 h^-1), but did increased the activity of soil urease (0.82 and 0.46 mg g^-1 24 h^-1) by 80.1% and of soil catalase (1.18 and 1.07 ml KMnO₄ g^-1 h^-1) by 10.1%. No significant difference was observed between warming OTCs and control plots in soil microbial biomass carbon (0.85 and 0.75 mg g^-1), microbial biomass nitrogen (0.07 and 0.06 mg g^-1), microbial biomass phosphorus (0.013 and 0.011 mg g^-1) and soil microbial respiration (6.1 and 6.3 μmol m^-2 s^-1). Correlation analysis indicates that the significant monthly variation of soil microbial biomass was related to changes in soil water content and soil organic matter. Warming altered soil microbial community structure, but did not affect much carbon-recycling-related soil enzyme activites, soil microbial biomass and soil microbial respiration. Maybe the warming is not long enough in duration or not great enough in magnitude to significantly alter the activity of soil microbes.