Phytoliths are microscopic siliceous bodies, composed of biogenic opal that serve for the steady vertical position in many grass plants of open lanscapes and fulfill other different functions for plants. In this article, the most common information about phytoliths is given. Vast bibliography on phytoliths concerns their morphology and taxonomic significance for the plant is represented. A new method of chemical treatment of actual plants and the Quaternary sediments to obtain phytoliths is proposed. By way of illustration of phytolith study we showed the first data on phytoliths from recent plants of coastal plain of the Atlantic Ocean in extreme southern Brazil and from different by lithology Holocene sediments. Represented materials on phytoliths may serve as starting point for the phytolith study in the Quaternary sediments of Moldova for the detail regional geological scheme, lithological facie correlation, paleoenvironmental and paleoclimate reconstructions, and using for archaelogical site study