The basic contractile unit of the mature skeletal muscle fiber, the sarcomere, represents a highly organized and elaborate forceproducing structure which consists of contractile proteins and associated regulatory proteins as well as an increasingly complex array of cytoskeletal proteins.The cytoskeletal system of the sarcomere has been subdivided into two distinct domains: the endosarcomeric lattice and the exosarcomeric lattice.Although rarely referred, the microtubule network of the skeletal muscle cell could be considered a component of the exosarcomeric lattice.Microtubules are found in the inter-myofibrillar space and appear to wrap around the myofibrils in a helical fashion, thus displaying a variety of orientations.Tubulin, the subunit of microtubules, is a heterodimer, composed of similar 50-kDa globular α and β ubunits.Microtubule associated protein, MAPs as an important structure, could make microtubule relatively stable.Intracellular localization and content of tubulin was found to be muscle type-specific, with high amounts in oxidative muscles, and much lower in glycolytic skeletal muscle.Tubulin is a plausible candidate because this cytoskeletal protein is known to interact with mitochondria.Tubulin shows saturable, high-affinity binding to intact mitochondria and hence to mitochondrial outer membrane,although the region of tubulin responsible for binding has not yet been identified.Immunoprecipitation experiments demonstrated a specific association of VDAC with tubulin, which indicates that VDAC could be a receptor for tubulin binding to mitochondrial outer menbrane.Our previous study confirmed that mitochondria regularly arranged on both sides of the line Z in the rest group.4-week eccentric exercise caused mitochondria accumulating in the skeletal sarcolemma, and mitochondria displaying either bigger or smaller.Thus, we proposed the hypothesis that eccentric exercise could induce tubulin and MAPs overexpressing, and the interaction of MAPs and VDAC could affect the mitochondria morphology and function.