Анотация: The technologies for biogas production, based on anaerobic digestion, become more and more widely applied in the practice in Bulgaria and worldwide. Most of them have problems such as ineffective biogas production and/or production of biogas with low quality. The monitoring of the processes solely by chemical, physical and technological parameters is not sufficient and is the reason for the ineffective performance of the technologies. There is need to be implemented strategies for functional control of the biological system carrying out the process of anaerobic digestion. In this review the most modern worldwide enzymatic, fluorescent and molecular methods and parameters for functional control of the technologies for biogas production are discussed