Lianas of a seasonal semideciduous forest Paulo de Faria northern São Paulo State Brazil). Lianas are soil-germinating plants perennially rooted that need support to reach the canopy. In tropical forest they are an important form of life due to their diversity they are part of the forest structure and source of food for various animals species. The aim of this study was to evaluate the species composition the diversity and the structure of a liana community in a seasonal semideciduous forest at the Ecological Station of Paulo de Faria São Paulo Brazil. The sampling included lianas specimens with DBH > 1 cm collected in 100 plots of 10 x 10 m (1 ha). We collected 1427 individuals representing 45 species. The species diversity (H’) was 2.98 nats individual-1. The richest families were Bignoniaceae (14 species) Sapindaceae (nine) Malpighiaceae (six) and Leguminosae (four) similarly to other neotropical forests. The families Bignoniaceae Sapindaceae and Apocynaceae were represented by a great number of individuals Melloa quadrivalvis (Bignoniaceae) was the most important species. The majority of the sampled individuals (57.6%) had diameters between 1-2.5 cm and in 26 individuals only the diameter was larger than 10 cm. If the purpose of a study of a liana community is to estimate the abundance our data suggest that all individuals with DBH > 1 cm must be sampled.