Abstract: 【Objective】 To study the diversity characteristics and spatial distribution pattern of dominant species of arbor in the Dacrydium pectinatum community in Diaoluo Mountain，Hainan Island，which could provide theoretical basis for the protection of biodiversity in the mountainous rainforest of Hainan. 【Method】 A 1 ha tropical forest dynamic moni‐toring plot was established in the Diaoluo Mountain rainforest of Hainan. All arbor plants with a diameter at breast height （DBH） 3 cm were recorded and surveyed，recording species names，breast circumference，tree height，crown width， and relative coordinates. Community composition，diversity indexes，spatial distribution patterns of dominant species and interspecific relationships were analyzed. 【Result】 Dacrydium pectinatum community in Diaoluo Mountain recorded 44 families of arbor plants，with 7 dominant families：Fagaceae（11 species），Pentaphylacaceae（10 species），Myrtaceae（9 species），Aquifoliaceae（9 species），Symplocaceae（6 species），Lauraceae（6 species）and Moraceae（6 species）. Eight dominant species were identified：D. pectinatum（356 plants），Dacrycarpus imbricatus（189 plants），Schefflera heptaphylla（161 plants），Daphniphyllum paxianum（136 plants），Alniphyllum fortunei（128 plants），Symplocos polianei （93 plants），Decaspermum cambodianum（63 plants）and Engelhardia roxburghiana（56 plants）. Rare species（1 plant） accounted for 40 species，33.61% of total species and 2.24% of total individuals. Within 1 ha tropical forest dynamic monitoring plot，1787 arbor plants（DBH 3 cm）belonging to 44 families，68 genera，and 119 species were recorded. The frequency of Dacrydium pectinatum with a DBH of 10-30 cm was relatively high，indicating a large number of individuals；the frequency of those with a DBH of 3-10 cm was relatively low，indicating a small number of individuals. Spatial analysis revealed random distributions at 0-10 m scale for Dacrydium pectinatum，Dacrycarpus imbricatus，Schefflera heptaphylla and Alniphyllum fortunei. Significant negative correlations were observed between Dacrydium pectinatum and Dacrycarpus imbricatus（5-12 m scale），Schefflera heptaphylla（6-12 m scale），and Symplocos polianei（6-20 m scale）. Populations of Dacrycarpus imbricatus，Schefflera heptaphylla and Daphniphyllum paxianum showed high juvenile individuals，indicating favorable regeneration. 【Conclusion】 Dacrydium pectinatum community in Diaoluo Mountain exhibits high arbor diversity and harbors numerous rare species，underscoring its high conservation value. However， the community is currently in an unstable stage with intense interspecific competition and frequent turnover of dominant species during succession.