Single-walled carbon nanotubes (SWNTs) are the ideal candidates for making next-generation electronic circuits because of their high strength, high toughness, high thermal stability, and superior electrical conductivity . However, achieving these goals is extremely challenging because the as-grown SWNTs contains mixtures of semiconducting (s-) and metallic- (m-) SWNTs, typically inadequate for integrated circuits. How to separate these two spcies according to their electronic structure and chemical activity has attracted much recent attention. Herein, this review focuses on the “in situ” metheds and techniques for the selective growth of s- and m-SWNT. Based on the understanding of the growth mechanism of those strategies, we try to propose the general guideline on that how can we develop the optimal condition for large-scaled growth of s- and m-SWNTs.