ABSTRACT: The study was conducted in Iringa municipality based on the factors influencing loss of biodiversity in Iringa municipality, A case of Ruaha ward. The study focused on exploring activities practiced in Ruaha Catchment Area which related loss of biodiversity. Both primary and secondary data were used. The methods of data collection were observations, interview and documentary review methods. Qualitative data were analyzed using statistical package for services solution (SPSS 20) which descriptive statistics including percentages was used. The results show that major factors lead to loss of biodiversity are agriculture, brick making, charcoal burning and livestock keeping. The most effects of these factors are drought, decline of water and loss of soil fertility. This is due to deforestation and use of artificial fertilizers. It is recommended that government should have information of regulation (increase fines to law breakers). Local communities should be actively involved in the decision-making and planning for conservation of biodiversity, enforcement of laws and establishment of by-laws so as to combat loss of biodiversity. Education and awareness about biodiversity conservation should be provided to the community members.