The aim of this study was to determine the green herbage and dry herbage yield, chemical and nutritional values and RFV of alfalfa (Medicago sativa L.) at different stages of maturity under Isparta ecological conditions in 2012. To achieve this goal random sampling plots was created according to an experimentation pattern, and the number of harvests was determined according to regional conditions. In chemical analysis, the following samples were analyzed for Dry Matter (DM), Crude Protein (CP), Ether Extract (EE), Ash, Crude Fiber (CF), Nitrogen Free Extract (NFE), Notral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF), as well as macro and micro minerals. The highest total green herbage yield was 9609.33 kg/da during the budding period, which decreased by 28% with maturity. The highest total dry matter yield, which depends on hay yield, was determined as 1742.63 kg/da at the beginning of the flowering period. The highest CP was determined during the budding period and decreased with maturity. DM, CS, NDF and ADF content increased while ash, Digestible Dry Matter (DDM), Total Digestible Nutrients (TDN), Dry Matter Intake (DMI), Metabolisable Energy (ME), Net Energy Lactation (NEL), and Digestible Energy (DE) content decreased with maturity. The highest RFV was determined during budding and the beginning of the flowering periods. Taking both yield and feed value results into consideration based on Isparta's conditions, the best harvesting period of alfalfa was determined to be at the beginning of the flowering period.