Abstract: Urban forestry plays an important role in maintaining the balance of urban ecosystem.With the heavier urban environmental and natural environmental stress,the causes of urban forest pests became more complicated,which threatened the urban landscape and habitat security.As logistics sites,cities are of higher risk of harmful biological invasion.From the viewpoints of the characters and functions of urban forestry,the authors explained the occurrence,causes and implications of biological disasters in urban plant environment based on ecological principles.According to the present situation of urban biological disaster prevention and control,the problems existed were pointed out and the countermeasures in preventing,monitoring and controlling these disasters were suggested.The management and research on urban forest health were prospected so as to promoting the sound development of urban forestry and making full play of the urban ecosystem.