This work aims to study the factors that affect the activity of actinomycetes in the production of antimicrobial whether they are anti-fungal and anti-bacterial. These factors are temperature, pH, concentration of sodium chloride salt (NaCl), carbon sources, nitrogen sources and the best media for the growth of actinomycetes. This was done on three isolates of actinomycetes AC2, AC9 and AC12). The results showed that the best temperature for the growth of the three isolates of actinomycetes was from 35-40oC, and the best pH for the three isolates was between 7 -7.2. The three isolates tolerated salinity with a concentration ranging from 2-5%. The best carbon source for the three isolates was starch, but with different concentrations. The best of carbon source for AC2, AC9 and AC12 was starch at concentrations of 20 g/l, 10g\l, and 25g\l, which gave inhibition zones 24, 45 and 34mm respectively. The results indicate that the best nitrogen source for AC2, AC9 and AC12 was ammonium sulfate at concentration 2.5 g/l, sodium nitrate at concentration 1.5g\l, and sodium nitrate at concentration 1.5g\l which gave a inhibition zones 20, 27 and 38 mm respectively.