A heterotrophic nitrifying bacteria strain Z01 was isolated from the sediment of Lake Nansi constructed wetland in winter, and it was studied for its capacity of nitrification and nitrogen removal. Methods of morphological, physiological and biochemical were used to identify strain Z01 as well as 16S rDNA analysis. It is affiliated to be Pseudomonas sp., which named Pseudomonas sp. Z01. These data showed that the optimum dosage, temperature, pH and salinity of microbial strains Z01 were 7%, 15℃, 6.0-8.0 and 0.3%, as sucrose as optimum carbon. Under the optimum removal efficiency of ammonia nitrogen from simulated wastewater by strain 10 was 1.1 times higher than that of heterotrophic nitrification medium. Moreover, it was better on the removal performance of the total nitrogen and COD in the simulated wastewater. Therefore, strain Z01 has a good application prospect and great development space in nitrification denitrification of sewage treatment in winter.