Climbing plants are an important component of tropical and subtropical forests. They have been increasing in abundance in tropical forests over the past several decades, which may lead to a reduction of forest biodiversity and ecosystem services, such as carbon stock and sequestration. Based on the literature community data of 355 quadrats from natural forests across Guangxi, we compared the species, phylogenetic diversity, and phylogenetic structural indices of climbing plants in karst forests with altitudes lower than 1000 m and non-karst forests with altitudes lower than 1000 m and above 1000 m (up to~2000 m). We also analyzed the relationships between the species diversity and phylogenetic diversity (PD), as well as the phylogenetic structural indices of climbing plants and mean annual temperature of the quadrat locations. The results showed that (1) the climbing plants in the natural forests mainly consisted of tropical genera (75.4%), with a low composition of temperate genera (12.3%); (2) the non-karst forests with altitudes ≤ 1000 m had the highest PD, and the karst forests had the lowest; (3) the species, PD, and phylogenetic structural indices of the climbing plants were not correlated with the mean annual temperature; (4) the phylogenetic structure of the climbing plants in the non-karst forests tended to be over-dispersed, indicating that competitive exclusion is the main mechanism for community assembly of climbing plants in these forests. The phylogenetic structure of the climbing plants in the karst forests tended to be clustered, indicating that environmental filtering is the main mechanism of the species assemblage. These findings reveal insights into the species diversity and co-existence mechanisms of climbing plants in tropical and subtropical forests.