A well-known blue - green algae Spirulina platensis is widely used in India for the management of different ailments. This study aims at extraction, purification and antiangiogenic screening of C-Phycocyanin isolated from Spirulina platensis. Preliminary analysis was performed for Spirulina platensis. Then, it was treated for the extraction of C-Phycocyanin by different extraction procedures, purified and finally characterization was achieved by reverse phase HPLC and by Mass Spectrometry. Antiangiogenic potential was screened by chick chorio allantoic membrane assay (in vivo), sponge implantation method (in vivo), morphogenesis assay (in vitro), cell migration (in vitro) and by cell proliferation assay (in vitro). The test and the other groups were compared with control group by one way ANOVA, followed by Dunnett’s test, to compare means of other groups with control mean. Chick chorioallantoic membrane assay, evaluated the number of branching points and angiogenic score and strong antiangiogenic results were detected for C-Phycocyanin at doses 10-5 M and 10-4 M. Good decrease in the sponge weights, number of new vessels formed, and the amount of haemoglobin were reported at the selected C-Phycocyanin doses in the sponge implantation method. On the endothelial cells, C-Phycocyanin (1-100 nM) exhibited potent reduction in proliferation, migration and in the length of tubes with increasing doses. C-Phycocyanin exhibited potent antiangiogenic effects in a dose dependent manner.