Nuclear DNA of eukaryotic organism attaches to the proteinaceous nuclear matrices via specific matrix attachment regions (MARs). In order to investigate the interactions between chromosomal DNA and nuclear matrices,we isolated the MARs from unicellular alga Dunaliella salina. As the first step,a random MAR library was set up and then the binding affinity of the selected clones to nuclear matrices was tested in this study. Three DNA fragments were found to bind specifically to the nuclear matrices in vitro,of which two were strong binders and all contained known consensus motifs and a hairpin loop structure of MAR.