Fifty nine species of blue-green algae belonging to nine genera and two families were collected from four different districts of Punjab, Pakistan. These districts are Gujranwala, Gujrat, Sialkot and Narowal. The collected species were taxonomically identified Most of the species were collected in the start of summer season at variable temperature. pH and EC was also measured and it was observed that Spirulina, Oscillatoria and Lyngbya were widely distributed genera. It was found that maximum pH was of O. annae i.e. 10.8 and minimum was of two species i.e. O. prolifca and O. anguina i.e. 7.1. Minimum Electrical conductivity (EC) was of O. prolifica and O. anguina i.e. 53 and the maximum EC was of Lyngbya truncicola which is 205.
















