Three new acylhydrazones containing pyrazine ring (C12H11N5O2·CH3COOH,1;C13H13N5O·2CH3COOH,2;C13H13N5O3·C13H13N5O3,3) were synthesized and fully characterized.The single-crystal XRD indicated that both 1 and 2 crystallized in monoclinic,P21/c space group but 3 belonged to monoclinic,C2/c space group.The temperature of the maximum thermal decomposition peaks measured by thermogravimetry for 1～3 is 284,289 and 276 ℃ respectively,all showing better thermal stabilities.The interactions of 1～3 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were studied by UV-Vis absorption spectroscopy and fluorescence spectroscopy,respectively,presenting that 1 ～3 could bind to CT-DNA via groove binding mode and quench the fluorescence of BSA through static process.Moreover,molecular docking studies of the interactions between 1～3 with DNA/BSA were in good agreement with experimental results.From antimicrobial activities of 1 ～3 and gentamycin sulfate against Staphylococcus aureus,Escherichia coli and Salmonella typhimurium,it was inferred that 3 had generally stronger antibacterial activity than 1 and 2 and is more active against Staphylococcus aureus than gentamycin sulfate.The cytotoxic tests of 1～3 and etoposide on human lung cancer cells (A549) were carried out by using the MTT method.