Nannochloropsis oculata, was grown in four different culture media with different composition and was analyzed to study the effect of media on the biochemical composition of the microalgae. The species was cultured in Walne’s, Miquel’s, Chu#10 and f/2 media simultaneously, keeping the physicochemical factors viz. temperature (22oC), light intensity (2000 lux), pH (8.0) and salinity (35ppt.) constant. The microalgae were harvested in the late exponential phase of growth to carry out the biochemical analysis to find out chlorophyll a, protein, lipid and carbohydrate content. The results revealed that the culture media has significant effect on the biochemical composition of the micro algae thus influencing its nutritional status. The highest protein content was observed in the alga grown in Miquel’s medium (32.05%). The carbohydrate was highest when grown in Chu#10 medium (19.12%) and lipid content was highest when grown in f/2 (18.93%) medium. The protein and lipid content showed statistically significant variation in different media. N. oculata grown in Walne’s medium gave the maximum cell count, cell density and chlorophyll a content. But the protein, lipid and carbohydrate content of the species were significantly low compared to other culture media. The result showed that the nutritional status of the microalgae depends on the composition of the culture media used.