Abstract:D. radiodurans is one of the most radiation-resistant organisms known till today. The radiation-resistance of D. radiodurans is due to its efficient DNA-repair system. Pentose phosphate pathway acts as the centre of carbon metabolism generating nucleotide,NDAPH and the ribose needed for synthesizing nucleic acid. In order to explore the impact of PPP on DNA-repair system in D. radiodurans R1, the zwf gene which encodes the glucose-6-phosphate dehydrogenase (G6PD) were knocked out and the biophysical and biochemical difference between Δzwf and D. radiodurans R1 under UV radiation were analyzed. The lack of G6PD blocks the PPP in Δzwf. The results showed that the mutant Δzwf became more sensitive to UV radiation, and the sensitive phenotype can be fully and partially compensated with gluconic acid-lactone or D-Ribose. Additionally, the content of metabolites, such as D-ribose, NADPH, IMP and UMP, in Δzwf has decreased. The current results suggest that PPP provides substrates and energy for the DNA-repair system in D. radiodurans R1 and plays an irreplaceable role in the UV radiation resistance. The result of the study provides reference for the mechanism of DNA damage reparations.