Time Division Synchronous Code Division Multiple Access (TD-SCDMA) or UTRA/UMTS-TDD 1.28 Mcps Low Chip Rate (LCR), is an air interface found in UMTS mobile telecommunications networks in China as an alternative to W-CDMA. Together with TD-CDMA, it is also known as UMTS-TDD or IMT 2000 Time-Division (IMT-TD).

The term "TD-SCDMA" is misleading. While it suggests covering only a channel access method based on CDMA, it is actually the common name for the whole air interface specification.

TD-SCDMA uses the S-CDMA channel access method across multiple time slots.

TD-SCDMA was developed in the People's Republic of China by the Chinese Academy of Telecommunications Technology (CATT), Datang Telecom, and Siemens AG in an attempt to avoid dependence on Western technology. This is likely primarily for practical reasons, since other 3G formats require the payment of patent fees to a large number of Western patent holders.

TD-SCDMA proponents also claim it is better suited for densely populated areas. Further, it is supposed to cover all usage scenarios, whereas W-CDMA is optimised for symmetric traffic and macro cells, while TD-CDMA is best used in low mobility scenarios within micro or pico cells.