Diversity of Crenarchaeota was investigated in eight terrestrial hot springs (pH 2.8-7.7; temperature 44-96 degrees C) located in Tengchong, China, using 16S rRNA gene phylogenetic analysis. A total of 826 crenarchaeotal clones were sequenced and a total of 47 operational taxonomic units (OTUs) were identified. Most (93%) of the identified OTUs were closely related (89-99%) to those retrieved from hot springs and other thermal environments. Our data showed that temperature may predominate over pH in affecting crenarchaeotal diversity in Tengchong hot springs. Crenarchaeotal diversity in moderate-temperature (59-77 degrees C) hot springs was the highest, indicating that the moderately hot-temperature springs may provide optimal conditions for speciation of Crenarchaeota.