In this study Dunaliella sp. was isolated from the hypersaline Lake Tuz and its cell density, dry matter, chlorophyll a, and beta-carotene production were studied in a batch system. The aim of this research was to determine the optimal conditions for Dunaliella sp. growth. Therefore 3 different temperatures (18 degrees C, 22 degrees C, and 26 degrees C) with 3 different salinities (25 parts per thousand, 30 parts per thousand, and 35 parts per thousand) were tested over a 19-day study. Significant differences were found at the end of the cultivation period (P<0.05) for 18 degrees C and 26 degrees C. No statistically significance were reported for all tested salinity degrees (P>0.05). At the end of the experiment the maximum growth were noticed for 18 degrees C 25 parts per thousand in which the culture reached 3.48 105 cell/ml. The lowest was reported for 26 degrees C 35 parts per thousand (1.50 105 cell/ml). The culture of 18 degrees C 25 parts per thousand had also the best chlorophyll a concentration and biomass amount. For the beta-Carotene 22 degrees C 30 parts per thousand (4.39 10 -6 mol/l) had the highest accumulation. The optimum temperature for Dunaliella sp. growth was 18 degrees C at 25 parts per thousand.