A new method to reconstruct the sediment transport pathways, which is based on the sediment grain-size distribution and uses principal component analysis (P-GSTA), is proposed here. In this method, a linearly-combined value of six grain-size parameters (mean, coefficient of variance, skewness, kurtosis and log-ratios of mud and gravel contents) with different weighting factors is used as a proxy of sediment transport processes. The combination of this method and cluster analysis is very effective to reconstruct sediment transport patterns in the depositional environments where compositive depositional processes exist.