Abstract: Calcium is an indispensable nutrient element for plant growth and development. The calcium ion（Ca2 ＋） is a versatile intracellular messenger that is involved in numerous signalling pathways. In order to explore the regulatory mechanism of calcium homeostasis in plants, we isolated total RNA from Arabidopsis thaliana seedlings induced with low Ca2＋. First, SMART c DNA synthesis technology was used to create a c DNA pool with end sequences homologous to the prey vector p GADT7-Rec. Then we co-transformed Y187 Yeast Strain and allowed the yeast to perform a recombination step between the linear prey vector and the c DNA. The c DNA library induced by low Ca2 ＋in Arabidopsis thaliana was thus constructed. The library capacity is about 3×10^9cfu/m L. The length of the insertion fragments ranges from 200 to 2 700 bp with an average length of 760 bp and the positive clone rate is 79.2%. These data suggest that the c DNA library is in high quality and suitable for screening the interacting proteins in Arabidopsis thaliana.