Green microalga, Dunaliella, isolated from the saltpan of Tamil Nadu, India, was identified both morphologically and genetically via 18S rDNA specific primers. Amplified 18S rDNA of Dunaliella salina were sequenced and submitted in the GenBank, NCBI. The natural β-carotene from optimally grown cells was purified by column chromatography, which was confirmed by Thin Layer Chromatography (TLC) with the Retardation factor value of 0.92. It was also quantified by High Performance Liquid Chromatography (HPLC) with a quantity of 3mg/mL of culture. The extracted β-carotene was assessed for its anticancer property in the human prostate cancer cell line (PC-3) which showed the effective apoptosis of 32% than the synthetic β-carotene which is 27% in flow cytometry analysis. Cytochrome c and caspase assay were also revealed that algal β-carotene mediated cell death was more compared to standard β-carotene. The Indian isolate, D. salina EU5891199 that has a potential effect on PC-3 cells has been documented in the present study.