The unique properties of the green fluorescent protein GFP (Green Fluorescent Protein) are the main reason for the widespread use of this protein in cell biology and molecular biology. In this work will be presented the most important ways to use GFP, such as monitoring gene expression study of intracellular dynamics and interactions of proteins and so-called. biological monitoring. The recent discovery of GFP-like proteins extends the well-known research techniques, in which the protein is used, and also gives rise to new hopes that in the near future will be applied in complex cytological and proteomic experiments.