Calmodulin (CaM), a ubiquitous calcium-binding protein, regulates diverse cellular functions by modulating the activity of a variety CaM-binding proteins (CaMBPs). Because eukaryotes have multiple CaMBPs, it is important to isolate and characterize them in different tissues and conditions. So far a number of CaMBPs have been identified through classical screening methods. Many classes of proteins have been predicted to bind CaMs based on their structural homology with already known targets. In an effort to develop a method for large-scale analysis of CaMBPs in Arabidopsis, we have generated a transgenic plants overexpressing AtCaM2-GFP. We performed protein pull-down assay to test whether exogenously expressed AtCaM2-GFP proteins can interact with CaMBPs. The exogenously expressed AtCaM2-GFP could strongly interact with a CaMBP, AS1 protein. This result suggests that AtCaM2-GFP in transgenic plants may interact with many CaMBPs in plant cell. Therefore, we will be able to isolate kinds of CaMBPs by using these transgenic plants in many different tissue and environments.