Between August 2007 and November 2008 was determined species composition, richness and abundance of trees with 10 cm DBH in an area of 10ha of forest in the Regional University Center of Los Santos (Los Santos, Panama) located 7 47 '30 .14 "North and 80 ° 16'30 .87" West. At each site, an area of 50m2 divided into 5 x 50m transepts was sampled. There were 850 individuals, represented in 77 trees and shrubs species, distributed in 31 families. The families with the most number of species were Fabaceae (15) and Rubiaceae and Flacourtiaceae with 5 species each. These results are consistent with expectations for lowland forests of the Neotropics. We identified two vertical strata in the forest. The total species richness and tree species has a correlation of 0.71. The diversity of the forest as biotypes is represented by 72.72% of trees, shrubs 27.27%. According to Margalef, Shannon and Fisher indices richness and diversity of species were significantly (p <0.05) lower in the shrub layer, in contrast, Simpson and Shannon indices showed no significant differences among the groups. Seven species protected by ANAM were identified, two of them by CITES and six by IUCN. Results indicate that the studied forest is very diverse and has a great importance for studies of plant diversity and conservation.