This work presents in-situ controlled growth of carbon nanotubes (CNTs) by local synthesis using silicon MEMS structures. The site-specific local synthesis and assembly of CNTs took 20 ~ 60 seconds experimentally to connect across a 5 ~ 10 mum gap to accomplish integrated CNTs. Using this method, we can now control the number of CNT connections between the silicon structures. The electrical properties of the silicon/CNT/silicon system show the linear current-voltage characteristics, indicating the ohmic contact behavior at the heterojunctions.