The invention refers to a weft-insertion-condition display method for a loom which includes a display device and in which a weft arrival time is detected each time a weft insertion operation is performed, the display device calculating statistics regarding the weft arrival times for each of predetermined sampling periods on the basis of the detected weft arrival times, storing the statistics that are sequentially calculated during a weaving operation in time series, and graphically displaying the stored statistics in time series along a time axis, wherein the weft-insertion-condition display method is characterized by comprising the step of: displaying information regarding a cause of variation in a travelling motion of a weft yarn on the same screen as a display screen on which the statistics are displayed the information being at least one of information regarding a reset operation for resetting the weft-insertion operational condition to an initial value after the weft-insertion operational condition is changed in the loom that performs a weft insertion control operation for changing a weft-insertion operational condition in accordance with weft arrival angles, information regarding a change in a weft insertion pattern, information regarding a change in a warp shedding pattern, information regarding a change in a weft density, and information regarding a change in rotational speed of the loom.