Seaweeds or marine macro algae constitute one of the commercially important renewable marine living resources. They are one of the ecologically and economically important living resources of the world oceans. Seaweeds contain different vitamins, minerals, trace elements, proteins and bioactive substances. They are an extraordinary source of colloidal minerals and trace elements. Analysis of heavy metals such as Manganese (Mn), Copper (Cu), Cobalt (Co), Zinc (Zn), Chromium (Cr), Nickel (Ni), Lead (Pb) and Cadmium (Cd) were done in three Ulva species viz, Ulva reticulata, Ulva lactuca and Ulva fasciata of the class Chlorophyceae. Algal samples were collected from Thikkody from Kerala and Mandapam from Tamil Nadu coast. There was a comparable variation was found in heavy metal concentration among the studied seaweed samples and location wise difference was also noticed. The results indicated that different species possessed various degrees of metal accumulation. Among the heavy metals studied, Mn was found to be high in all the algal samples in both localities. It was observed that Zn concentration was found to be high in all the species of Ulva from Tamil Nadu compared to Kerala. It was found that the concentration of Pb was below the Acceptable daily Intake (ADI) in all the studied samples from Tamil Nadu coast. General trend found in the present study was that more quantity of heavy metals from Thikkody compared to Mandapam.