Abstract: This study aimed to investigate the ecological functions of periphytic ciliates in intensive mariculture waters The changes of community structure for periphytic ciliates in intensive marine shrimp farming pond were investigated during the whole shrimp culturing period of 140 days, aswell as their responses to environmental factors. Glass slideswere used as artificial substrates for collecting ciliates from a closed intensive shrimp farming pond near Qingdao, China. The environmental factorswere also collected during the whole experimental period. A total of 41 species of ciliates which belong to 21 genera were identified, and among them, Zoo thamnium and Pseudovorticella were the dominant genera. Peaks of ciliate abundance occurred on about 100d and 120d, respectively, and the maximum of species number occurred on the 80d, both of them mainly due to the ciliates which belong to peritrichida. The changes of species richness, diversity and evenness indices generally showed the similar tendency, and two peaks appeared on 60d and 110d, respectively. Results of multivaria teanalysis suggested that the similarity was prominent among the ciliate community structures detected on 130d, 140d and time points before the 90d, and decreased gradually compared to community structures detected on 110d, 100d and 120d. The relationships between community structural parameters of periphytic ciliates and water quality factorswere analyzed. The structural parameters presented significant correlations (Pearsonps correlation coefficient) with several environmental factors. The concentration of ammoniumnitrogen showed signi ficantly positive correlations with species number(p ppp <0.05); while the concentration of soluble reactive phosphate was demonstrated to be remarkably positive correlated with the abundance and species number (p <0.01). The results showed that the community of periphytic ciliates had good capability to adapt to the eutrophic environment.