In consonance with De La Salle Lipa’s active participation in the reforestation efforts being done as it supports the One Million Trees and Beyond Project of De La Salle Philippines and Lasallian Institute for the Environment, this descriptive study determined diversity of mangrove species of Mataas na Bayan and Palanas Lemery, Batangas. A total of 8 quadrats measuring 10m x 10m were laid along the low intertidal zone and mid- intertidal zones of the mangroverforest blocks. Data on frequency and density parameters were gathered from these quadrats. A total of 153 mangrove trees belonging to 13 species were found in the two study sites. The 113 mangrove trees in Mataas na Bayan have average girth at breast height of 29.42 cm; average height of 4.07 m; average crown of 1.93 m; and average diameter at breast height of 9.36cm, while the 40 mangrove trees in Palanas have average girth at breast height of 43.89 cm; average height of 6.74m; average crown of 2.82m; and average diameter at breast height of 13.97cm. The Palanas mangrove forest is found to have a relatively higher species richness of 12 and diversity index of 2.276 than that of Mataas na Bayan’s species richness of 9 and diversity index of 1.318. These diversity results indicate that Lemery is home to different mangrove species, which justifies the essentiality for mangrove management, protection and reforestation.