A device for inserting yarn on a yarn-holder cop in winding apparatus, of the type comprising a part for trapping and inserting yarn on the cop moving between a backward rest position and a forward position for insertion of the yarn on the yarn-holder cop. For cutting a lower branch of yarn, there is provided a cutting part having a first and a second cutting element moving one in respect of the other for cutting the yarn. Structure is provided for trapping the lower branch of the yarn and for driving the cutting part which can be actuated and are actuated mechanically by the yarn insertion part. The yarn cutting part is arranged near the yarn-holder cop at the point of insertion of the yarn by the yarn insertion part.