The geomorphologic features called tiankengs were first discovered and named at the end of the twentieth century in karst areas of China. They have enjoyed increasing attention owing to their unusual geologic processes and unique ecological communities. However, the understanding of classification, geomorphic evolution, developmental conditions, geological dating and ecological environments of tiankengs are still extensively disputed by geomorphologists and geologists. This article focuses on combining all main areas of recent research activities from three aspects: development, evolution and transformation of karst tiankengs; biodiversity of karst tiankeng forests; and the impact of human activities on karst tiankeng ecosystems. Finally, we suggest future direction for research on karst tiankeng ecosystems: (1) multidisciplinary systematic study; (2) processes of ecological change and environmental effects under the influence of both natural and human impacts; (3) research on their protection, rational utilization, and sustainable management. Keywords Tiankeng * Evolution * Doline * Species diversity * Habitat heterogeneity