Abstract: Current research advances on CNT arrays are reviewed with an emphasis on synthesis. The growth mechanism, structure modulation and mass production of CNT arrays are also discussed. Various applications of the as-grown CNT arrays, CNT yarns and dispersed CNTs from the arrays in a composite, strength enhancement and functional devices are also summarized. It is pointed that the research trend on CNT arrays should be emphasized for the large scale production of CNT arrays and their applications.