Statistical characteristics of pressure drop fluctuations have been investigated experimentally in order to obtain fundamental data for flow pattern identification of two-phase flow in a horizontal pipe. The experimental results show that the horizontal flow of nitrogen gas (or air) -water mixtures exhibits peculiar features of statistical properties (PDF, PSD), that its flow patterns can be classified by using the statistical features, and that the pressure drop fluctuations measured at a short interval of pipe have high sensitivity to flow change. The results suggest that it is possible to identify the flow patterns of horizontal two-phase flow on the basis of the features of statistical parameters (standard deviation and coefficients of skewness and excess.