In this paper aspects of bed load movement in rivers are presented. Because of the its overview character and wide matter raised, the paper is divided in to two parts. In the first part the bed load characteristic and division are presented. The beginning of the grain movement in aspects of shear stress, the Shield’s criteria with different grain shape and diversified grains exhibition to moving force are presented. Authors give an attention to the Shield’s curve ambiguous connected with different grain movement, grain expose to moving force. Because of this approach the range of the Shield’s curve apply is larger. In this paper the ranges of stress as the limit of grain stability/movement taking into consideration of blocking small grains are presented.

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