Particle size analysis are one of the most common methods to describe the sediment size distribution. Many methods are available for quick examination of particle size, but for coarse grain deposits there are some restrictions on their use. This article compares the results obtained from three most popular analyses of these deposits: direct measurement of axis „b” (Wolman method), sieve and digital – planimetric analysis. The results show significant discrepancy of the data obtained. The Wolman method do not take into account particles smaller than 2 mm and the accuracy of analysis is strongly dependant on sample size. Digital analysis (planimetric) took into account sandy fractions but analysis quality depends on the resolution and lighting. For the inference of the depositional environment dynamics, reliable data provides sieve analysis.