Double-stranded M13mp18 DNA was irradiated with 30keV carbon ions in dry state under vacuum to investigate the low-energy heavy ion induced mutation spectra. When the irradiated DNA was used to transfect Escherichia coli JM105, 3.6-5.7-fold increases in mutation frequency were observed, in contrast to the spontaneous group. Sequences of the 92 induced mutants showed that the carbon ions in this study could induce an interesting mutation spectrum in the lacZα gene. One-base mutations (96.8%) and base pair substitutions (56.4%) were predominant, most of which involved G:C base pairs (90.6%), especially G:C -> T:A transversions (49.6%) and G:C -> A:T transitions (39.6%). This is similar to the spectra induced by γ-rays in the same ds M13, wild type E. coli system. We also found a considerable amount of carbon ion induced one-base deletion (38.5%) and the mutation sites distribution on the target lacZα gene was obviously non-random. We compared this study with previous data employing γ-rays to discuss the possible causes of the mutation spectrum.