Abstract: A regional common-use block for a CATV system, which can be flexibly managed with increased convenience according to regional requirements, and which does not require a large-scale installation at each subscriber location, thereby lowering cost to each subscriber. Additionally, a CATV system using a plurality of the regional common-use blocks wherein a regional common-use block is interposed between a CATV center and each subscriber instrument and includes a set-top-converter (STC) which is commonly held by a specified unit number of subscribers in a local area, and wherein switching control is conducted to transmit an output of a STC to a plurality of subscribers. The common-use block separates multiplexed signals from the CATV center, converts the separated signals by each STC, controls circuit switching means, modulates the signals by RF modulating means and subsequently transmits the requested programs to subscribers.