In order to breed Rhodospirillaceae bacteria with high temperatureresistance and saltresistance for powdery agentmanufacture, the conditions of protoplast fusion between saltresistant Rhodospirillaceae bacteria which could degrade Nnitroso over 90% and Bacillus stearothermophilus which grew at 60-70 ℃ were studied using orthogonal test. The physiological characteristics of fusants such as temperature, growth salt and purifying the water were determined and the identifications between parent strains and the excellent fusant by electron microscope and absorption spectroscopy were studied. The results showed that the optimal conditions of protoplast fusion were as follows: temperature 37 ℃, reaction time 3h and the adding amount of PEG 40%.Under these conditions, the rate of protoplast fusion was 1.536% and three fusants(a,b,c) which could grow well at 30-50 ℃ were obtained. The tolerance of growth temperature of three fusants was improved by 66% than saltresistance Rhodospirillaceae bacteria, but some characteristics of saltresistance ,degrading N ammonia and Nnitroso were similar to it. Fusant a grew faster and steadier than other fusants and its characteristics of cell shape, Gram stain and pigment absorbing peak were similar to saltresistantRhodospirillaceae bacteria.