This study was implemented to determine the effects of lactic acid bacteria (LAB) inoculants and/or enzymes on the fermentation, aerobic stability and in vitro organic matter digestibility characteristics of alfalfa ensiled at different stages of maturity. Alfalfa was harvested at three levels including early, middle and full flowering stages. In this research, inoculant-1188 (Pioneer®, USA) and enzyme (Global Nutritech, TR) were used as lactic acid bacteria, enzyme and as lactic acid bacteria+enzyme mixture inoculants. Proceeding the treatments of these inoculants to silages at 6.00 log10 cfu/g levels, the chopped alfalfa was ensiled in 1.0 liter special anaerobic jars, equipped with a lid enabling gas release only. The jars were stored at 25±2°C under laboratory conditions. Microbiological and chemical analyses were done through four jars sampled from each group on the 45th day of ensiling process. At the end of the ensiling period, in vitro organic matter digestibility test was done and all silages were subjected to an aerobic stability test for 5 days. The results showed that LAB and/or enzymes increased the characteristics of fermentation but decreased cell wall content. There was no effect determined on aerobic stability and in vitro organic matter digestibility of alfalfa silages.