A parallel computer system comprising a plurality of nodes multi-dimensionally connected with one another in a mesh or torus configuration, each node comprising a routing controller and an information processor, characterized in that each of the nodes includes: a first receiving storage device configured to store data to which a first virtual channel is allocated, and a second receiving storage device configured to store data to which a second virtual channel is allocated, wherein the first and second receiving storage devices are included in cross-bar interfaces in the corresponding data transmitting and receiving directions; a virtual channel control unit configured to refer to information in a header of the stored data and compare a position in a dimension of a destination node with a position in the same dimension of its own node, and if the comparison result indicates that the position of its own node matches a position one node before the position of the destination node, change one of the first and the second virtual channels allocated to the stored data to the other one of the first and the second virtual channels; a transmitting dimension control unit configured to perform dimension order routing by referring to information in a header of the stored data and comparing the position in the dimension of the destination node with the position in the same dimension of its own node, and if the position of its own node matches the position of the destination node, change the dimension in which the stored data are transmitted into a subsequent dimension, and if position of its own node does not match the position of the destination node, retain the dimension in which the stored data is transmitted; and a cross-bar switch configured to perform arbitration between a unit of data stored in the first storage device and a unit of data stored in the second storage device, and determine one of the units of the data to be transmitted in a corresponding one of directions as data to practically be transmitted. a first receiving storage device configured to store data to which a first virtual channel is allocated, and a second receiving storage device configured to store data to which a second virtual channel is allocated, wherein the first and second receiving storage devices are included in cross-bar interfaces in the corresponding data transmitting and receiving directions; a virtual channel control unit configured to refer to information in a header of the stored data and compare a position in a dimension of a destination node with a position in the same dimension of its own node, and if the comparison result indicates that the position of its own node matches a position one node before the position of the destination node, change one of the first and the second virtual channels allocated to the stored data to the other one of the first and the second virtual channels; a transmitting dimension control unit configured to perform dimension order routing by referring to information in a header of the stored data and comparing the position in the dimension of the destination node with the position in the same dimension of its own node, and if the position of its own node matches the position of the destination node, change the dimension in which the stored data are transmitted into a subsequent dimension, and if position of its own node does not match the position of the destination node, retain the dimension in which the stored data is transmitted; and a cross-bar switch configured to perform arbitration between a unit of data stored in the first storage device and a unit of data stored in the second storage device, and determine one of the units of the data to be transmitted in a corresponding one of directions as data to practically be transmitted.