Microtubules are the key elements of the cytoskeleton responsible for cytoplasm organization and intracellular transport. Their functions are realized mainly via microtubule associated proteins (MAP), the minor components bound to the microtubule core. Among MAP there are so-called structural proteins which control tubulin polymerization and provide the "static" interaction of microtubules with other intracellular components and translocator proteins. The latter are capable of moving the material along microtubules; this process is coupled with ATP hydrolysis. The first section summarizes the data on the composition and changes during ontogenesis and functioning, such as influences on tubulin polymerization and promotion of interactions between individual microtubules, between microtubules and microfilaments and neurofilaments as well as between microtubules and membrane organelles (lysosomes, golgi stacks, mitochondria). The second section deals with the description of translocators. The biochemical properties of the following proteins are considered: i) kinesin, the protein translocating particles to the distal end of microtubules and, ii) dynein which promotes translocation in the opposite direction.