Cysteine-rich 61 (Cyr61), a secreted protein which belongs to the CCN family, has been found to be differentially expressed in many cancers and to be involved in tumor progression. The expression of Cyr61 in esophageal squamous cell carcinoma (ESCC) has only recently been described, but the roles of Cyr61 in ESCC cells still remained unclear. In this study, we have shown that there are high levels of Cyr61 in ESCC cell lines. Furthermore, using RNA interference (RNAi), we stably silenced the expression of Cyr61 in EC109 cells, an ESCC cell line. The colony formation, MTT, cell migration, cell invasiveness and cell adhesion assays were employed to address the roles of Cyr61 in the growth, migration and adhesion of ESCC cells. The results have shown that Cyr61 knockdown by RNAi leads to a significant reduction of colony formation and cell growth. The migration and invasiveness ability of EC109 cells were also suppressed with the Cyr61 down-regulation. Furthermore, the adhesion of the EC109 cells was decreased in the Cyr61 knockdown cells compared to the control cells. Taken together, our data suggest that Cyr61 may play crucial roles in regulating neoplasm progression of ESCC.