Introduction: Continuing control of mental health would be helper in decreasing health problems. So, each health system need to data for mental health promotion that WHO present the special instrument WHO-AIMS.Aim: This study was done for knowing with WHO-AIMS tool, health problems diagnosis in different countries and assessing mental health in Iran by WHO-AIMS.Material & Method: This study was done by systematic review. The key words were Mental Health Systems, and World Health Organization Assessment Instrument for Mental Health Systems in Iran and abroad. In Iran there was not article in introducing WHO-AIMS. But in the world 93 WHO reports and 10 research articles were found that introduced the WHO-AIMS, its usage problems and its applied for assessing mental health systems in different countries.Results: The findings showed that WHO-AIMS have consisted in 6 domains (policymaking, country program, law and budget for mental health, mental health services, mental health in PHC, manpower, health education and other section in mental health for example control and research), 28 sub-scale with 156 items. Also, the main and majority of mental health problems in different countries were no mental health law, low mental health budget, high costs for psychosocial intervention, unsuitable distribution of psychiatric hospitals, no collecting data, staff shortage, not enough educated personnel in mental health, lack of association for patients and their families, not enough mental health services and etc.Conclusion: WHO-AIMS instrument shows a clear picture of threats and opportunities of mental health systems in countries, so they would be improved their mental health systems and implemented their policy in mental health. This study resulted to knowing mental health managers and staff with this instrument and also, researchers drive to develop new tools for assessing mental health system.