As synthesis determined the future, in this talk, I will focus on the chirality controlled growth of horizontal carbon nanotubes array with designed catalysts: (1) By using open-end SWNTs as ？seeds/catalysts‘ (without metal catalysts), duplicate SWNTs could be grown and cloned from the parent segments via an open-end growth mechanism. These findings provide a new approach for growing SWNTs with controlled chirality; (2) Using symmetry matching strategy, a structure-family (2m, m) horizontally aligned SWNTs were successfully obtained on uniform carbide (WC and Mo2C) solid catalysts. It is based on a consideration of nanotube/catalyst interfacial thermodynamics determined by symmetry, and the kinetic growth rates set by the number of kinks; (3) For the application of SWNTs in electronic device, a new family of semiconducting SWNTs, (n, n–1) carbon nanotubes, called property-family, with different diameters can be grown using near-equilibrium nucleation growth mode.