Nonviral gene delivery systems have been increasingly proposed as a safer alternative to viral vehicles. In the present study, we synthesized water-soluble chitin by aminoalkylating onto chitin at the C-6 position, and its transfection efficiency was investigated. Aminoethyl-chitin (AEC) was complexed with DNA, and AEC/DNA nanoparticles were characterized. AEC/DNA nanoparticles showed good DNA binding ability, high protection of DNA from nuclease and serum, and low cytotoxicity. Mean particle size decreased from 367 to 290 nm and. potential increased from -4.58 to 22.87 mV when the AEC/DNA charge ratio (N/P) increased from 1.15 to 18.5. The transfection efficiency of AEC/DNA nanoparticles was investigated in a human embryonic kidney cell line (HEK293), and the results showed that AEC/DNA nanoparticles were much enhanced compare with naked DNA.