Abstract: Objective To detect Leptospira interrogans in water with the DNA chip.Methods The water with different concentration of Lep to spirainter rogans and other pathogens were detected with DNA chip.The specificity and sensitivity of the DNA chip were observed with compaison of polym erase chain reaction(PCR).Results Positive signals were displayed on the micro chips for water samples with Leptospira interrogans and there was nosignal displayed forwater samples without Leptospira interrogans.The least detection sensitivity of the DNA chip and PCR were 5 and 10 Leptospira interro gans per 100 millmie tres water,respectively.The sensitivity of the DNA chip was higher than that of PCR amplification.The positive numbers of Leptospira in terrogans were 8,5,4 with the DNA chip,PCR and liquid culture,respectively for 20 water samples from epidemic areas.Conclusion Leptospirinterrogans in the water can be detected with the DNA chip more rapidly,specifically and sensitively.