A jacquard circular knitting machine provided with a needle cylinder driving mechanism capable of optionally and readily controlling the rotary motion of the needle cylinder according to the pattern to be knitted. A motor interlocked through gears or the like with the needle cylinder rotates according to a needle cylinder rotating procedure stored previously in a magnetic memory medium. Actuators operate according to a pattern forming procedure stored in another magnetic memory medium as a signal is provided by a sensor for detecting the rotary motion of the needle cylinder. Thus a jacquard circular-knitted fabric having predetermined patterns can be knitted efficiently. In addition to the above, a machine is provided with a third magnetic memory medium for storing a yarn feed element switching procedure to carry out a plurality of yarn feed element switching operations at optional timings when necessary while a single course of a fabric is knitted. A yarn feed element switching device is actuated according to the signals given thereto by the third magnetic memory medium as a signal is provided by the sensor for detecting the rotary motion of the needle cylinder. Thus a number of colored yarns exceeding the number of the yarn feed units can be stitched efficiently into a single course of a knitted fabric.
