Objective To investigate and evaluate the clinical effect of EDTA root canal irrigation solution combined with micro ultrasonic technique for root canal therapy in the elderly.Methods We collected 298 teeth in the elderly that needed root canal therapy and used EDTA root canal irrigation solution combined with micro-ultrasonic technique for root canal therapy.The clinical efficacy of root canal therapy was observed and evaluated two years after therapy.Results Two year after therapy,the root canal therapy was successful in 236 teeth,with the success rate of 79.18%.Conclusion The root canal therapy in the elderly by EDTA root canal irrigation solution combined with micro-ultrasonic technique is feasible and effective.