【Objective】Dry-wet alternation is a common phenomenon existing in nature, especially in paddy soil. But it is still unclear about rule of the response of soil microorganisms to such variation of soil moisture in complex soil, because of limitations in technology. This study was aimed to investigate rules of changes inabundance and community of archaea in a typical paddy soil derived frnom lacustrine sediment, in Changshu of Jiangsu, experiencing three cycles of drying and wetting in lab. 【Method】Soil samples of the typical paddy soil from Changshu were subjected to three consective cycles of drying and wetting in lab. Each of the drying or wetting period lasted 7 days. Real-time quantitative polymerase chain reaction (Real-time PCR) and high-throughput sequencing of 16S rRNA genes were performed to analyze how the archaea in the soil samples changed in biodiversity, abundance and community in response to the dry-wet alternations at DNA and RNA levels. 【Result】The Real-time PCR analysis suggests that the abundance of archaeal 16S rRNA genes copy number changed in response to dry-wet alternation, dropping at DNA level by 149 ~ 468 times, but only by 2.06 times on RNA level during the process from wet to dry, and rising by 147 ~ 360 times at DNA level, but only by 2.95 times at RNA level during the process from dry to wet. These findings indicate that the change of archaea in 16S rRNA genes copy number was far greater at DNA level than at RNA level. Based on the high-throughput sequencing of 16S rRNA genes, it was found that the archaea community changed significantly in structure at both DNA level and RNA level after three consecutive dry-wet cycles and the changes may be described by non-metric multidimensional scaling (NMDS) (p<0.05). The archaea in the paddy soil could be sorted into 3, 10, 13, 14 and 10 groups at either DNA or RNA level, when classified at phylum, class, order, family and genus level, respectively. The alternation caused significant changes in the archaeal community, especially the six groups at order level, including mainly Methanogenicarchaea and ammonia-oxidizing archaea, like Methanobacteriales, Methanosarcinales, Methanomicrobiales and Nitrososphaerales. The change varied by 2.1%, from 2.82% to 0.69% in total abundance and by 3.79 times, from 0.54% to 2.60%, in maximum fold. 【Conclusion】The Real-time PCR analysis demonstrates that the abundance of archaeal 16S rRNA genes copy number changed significantly in response to the alternation. The high-throughput sequencing of 16S rRNA genes indicates that the archaeal community in the soil changed significantly in structure with the soil alternating in soil moisture condition from dry to wet and from wet to dry. As in environment free extracellular RNAs decompose rapidly, while free extracellular DNAs may remain intact for quite a long time, it is quite probable that archaeal RNA sequence may come from intact microbial cells, and these archaeal cells are able to adapt to severe moisture changes in paddy soil. As the process of drying or wetting does have some impacts on abundance and composition of archaea communities, it is more advisable to unfold studies on changes in soil archaea at DNA and RNA levels simulataneously so as to expose rules of the soil archaea responding to dry-wet alternation of the soil.