6-Substitutedpurine and 9-beta-d-ribofuranosyl purine analogues were synthesized and their biological activities were evaluated. CD Spectra and thermal melting studies showed that compounds 8, 9, 10 could interact with RNA and DNA in solution. Compound 8 and 10 may bind with RNA single strand and interfere the formation of RNA duplex. Among of these compounds, compound 8 showed middle inhibition on