A resource scheduling method and apparatus, data transmission method and apparatus and communication system. The resource scheduling apparatus includes: a first receiving unit configured to, on a first BWP, receive downlink control information carried by a first control resource set; and a determining unit configured to, when a size of the downlink control information is determined by a second BWP, determine that a first starting position that is frequency domain scheduled on the first BWP is a second starting position of a frequency domain range of the first control resource set. Hence, more terminal equipments may be made to receive and share common messages and system resource overhead may be saved. And furthermore, it may be used to receive the dedicated message from the terminal equipment, so as to ensure robustness when the BWP is switched, thereby solving an existing problem.