A bobbin conveying system comprising: a stocker having a plurality of rows of stocker pegs and capable of hanging and storing a full bobbin and an empty bobbin on each stocker peg; a bobbin transfer robot that removes a full bobbin stored in the stocker and attaches the full bobbin to a creel of a yarn processing machine, and removes an empty bobbin from the creel and stores the empty bobbin in the stocker; a traveling creel cart having a plurality of rows of cart pegs and conveying a full bobbin or an empty bobbin hanging on each cart peg; and a controller that controls the stocker and the traveling creel cart, wherein the stocker is configured to be able to move full bobbins hung on the cart pegs of the traveling creel cart to the stocker pegs, and to move empty bobbins hung on the stocker pegs to the cart pegs, the number of rows of the stocker pegs provided by the stocker is equal to the number of rows of the cart pegs provided by the traveling creel cart plus one, and the controller, in a state in which one row of the stocker pegs is bobbin-less and empty bobbins are hung on all remaining rows of the stocker pegs, controls the stocker and the traveling creel cart so that the stocker and the traveling creel cart cooperatively perform an exchange operation of replacing empty bobbins in the stocker with full bobbins on the traveling creel cart by alternating the following processes: a first process of moving full bobbins hung on one row of cart pegs of the traveling creel cart to one row of the stocker pegs that is in a bobbin-less state to set one row of the cart pegs in a bobbin-less state; and a second process of moving one row of empty bobbins hung on the stocker pegs to one row of the cart pegs that is in a bobbin-less state after the removal of the full bobbins in the first process to set one row of stocker pegs in a bobbin-less state, as well as controlling the traveling creel cart, after the traveling creel cart has conveyed full bobbins to the stocker and exchanged the full bobbins with empty bobbins in the stocker, so as to convey the empty bobbins to a different location other than the stocker. a stocker having a plurality of rows of stocker pegs and capable of hanging and storing a full bobbin and an empty bobbin on each stocker peg; a bobbin transfer robot that removes a full bobbin stored in the stocker and attaches the full bobbin to a creel of a yarn processing machine, and removes an empty bobbin from the creel and stores the empty bobbin in the stocker; a traveling creel cart having a plurality of rows of cart pegs and conveying a full bobbin or an empty bobbin hanging on each cart peg; and a controller that controls the stocker and the traveling creel cart, wherein the stocker is configured to be able to move full bobbins hung on the cart pegs of the traveling creel cart to the stocker pegs, and to move empty bobbins hung on the stocker pegs to the cart pegs, the number of rows of the stocker pegs provided by the stocker is equal to the number of rows of the cart pegs provided by the traveling creel cart plus one, and the controller, in a state in which one row of the stocker pegs is bobbin-less and empty bobbins are hung on all remaining rows of the stocker pegs, controls the stocker and the traveling creel cart so that the stocker and the traveling creel cart cooperatively perform an exchange operation of replacing empty bobbins in the stocker with full bobbins on the traveling creel cart by alternating the following processes: a first process of moving full bobbins hung on one row of cart pegs of the traveling creel cart to one row of the stocker pegs that is in a bobbin-less state to set one row of the cart pegs in a bobbin-less state; and a second process of moving one row of empty bobbins hung on the stocker pegs to one row of the cart pegs that is in a bobbin-less state after the removal of the full bobbins in the first process to set one row of stocker pegs in a bobbin-less state, as well as controlling the traveling creel cart, after the traveling creel cart has conveyed full bobbins to the stocker and exchanged the full bobbins with empty bobbins in the stocker, so as to convey the empty bobbins to a different location other than the stocker. a first process of moving full bobbins hung on one row of cart pegs of the traveling creel cart to one row of the stocker pegs that is in a bobbin-less state to set one row of the cart pegs in a bobbin-less state; and a second process of moving one row of empty bobbins hung on the stocker pegs to one row of the cart pegs that is in a bobbin-less state after the removal of the full bobbins in the first process to set one row of stocker pegs in a bobbin-less state, as well as controlling the traveling creel cart, after the traveling creel cart has conveyed full bobbins to the stocker and exchanged the full bobbins with empty bobbins in the stocker, so as to convey the empty bobbins to a different location other than the stocker.