Petrophysical interpretation result is essential information for subsurface evaluation so we have to devote to reduce uncertainty of it. Although accuracy of interpretation parameters is regarded as critical factor of uncertainty of petrophysical interpretation result, measurement and interpretation model are not complete also so play important role of uncertainty in reality. Uncertainty analysis may help to find cause of uncertainty but it tend to assume perfection of interpretation method. In this paper, examples of problem of current measurement tools, flaw of interpretation and uncertainty analysis method are showed, and importance of understanding of cause of uncertainty, and validation with other information like oil/gas shows, are stressed to reduce the petrophysical interpretation uncertainty.
