Artemia plays a major role in aquaculture as one of the most important live foods used in larval rearing. The aim of this study was to determine the optimum level of feeding in Artemia urmiana with Baker's yeast (Saccharomyces cerevisiae). Triplicate groups were fed with different levels of S. cerevisiae yeast 0.625 (control), 1.25 (T1), 2.50 (T2), 5.0 (T3) (mg yeast per 1000 nauplii) for 10 days. Culture conditions such as temperature (29oC), Dissolved oxygen (5 mg/l), Salinity (60 g/l) and pH (8) were set according to Standard Method. At the end of the trial, total length, dry weight, survival rate and biomass production were measured. Moreover, average daily growth (ADG), body weight increase (BWI), specific growth rate (SGR) and condition factor (CF) were determined. The results showed that total length (2.10±0.14 mm), dry weight (11.75±1.91µg), biomass production (129.55±21.3 mg/l) and survival rate (62.2±12.2 %) of T2 were significantly higher than. Also ADG (1.12±0.19 mg), BWI (11.21±1.89) and SGR (30.71±1.41) were significantly higher in T2 compared to other treatments. The highest CF was observed in T4 (60.47±21.46) and the lowest was observed in T2 (22.89±3.01) (P<0.05). According to these results, the best level of Artemia feeding with S. cerevisiae was 1.25 mg of S. cerevisiae per 1000 Artemia nauplii. Also our results indicated that food efficiency depends on the amount of food available, and it was increased with food availability to a certain level.