The paper studies the relation between output and yarn forming quality of C60 card. Trials are run on C60 card to obtain different outputs by using same raw cotton and process but different delivery speed and same other technical parameters of carding process. The trial results show that when processing 29.5 tex and 36 tex yarns with the output between 60 kg/h and 150 kg/h, most yarn quality indicators such as Uster CV%, thick places/km, thin places/km and neps/km can reach the 5% line of Uster Statistics, some even reach the 25% line. This demonstrates C60’s high carding efficiency as well as high output and yarn quality.