Abstract： Objective To investigate the difference between the results of using two standards(CPI and No. 5 sharp probes) in the diagnosis of clinical dental caries during epidemiological survey. Methods The CPI and No. 5 sharp probes were used respectively for the diagnosis of clinical dental caries in the same group of children aged 12 by the two examiners. This group of children were reexamined after 14 days to compare the consistency and the rate of coincidence of the location of teeth and caries average and the prevalence rate of dental caries diagnosed by the two kinds of probes. Results The difference between the location of teeth with caries examined by the two different standards respectively by the same examiner was not statistically significant. The difference between caries average and the prevalence rate of dental caries examined with the two different standards respectively by the same examiner was also not statistically significant. The difference between the outcomes of the crossover comparison by the two examiners showed no statistical significance. Conclusions There was no significant difference between the two diagnostic standards for caries. The outcomes of the diagnosis based on beth standards shows a similarity. CPI couldreplace No. 5 sharp probes due to its convenience in large scale of oral health survey.