Developments in concepts and classification of Gleysolic soils in Canada throughout this century emanated from increasing knowledge of soils in this country and elsewhere. Some of the current problems in classifying these soils are shown to be due to a tendency to insist that soil taxonomy should be compatible with the current soil water regime. Separating soil water regime from soil taxonomy at the higher levels conveys additional information. Though more elegant bases of criteria were sought, soil color is still the most useful known property for differentiating Gleysolic soils from others. Results of recent proposals for fine-tuning the criteria of the Gleysolic order are incorporated into a revised draft of the order. Further work is required to resolve a few outstanding problems but the need for research on Gleysolic soils is minor in relation to that on other soil problems. The revised system requires testing in all regions and documentation of problems that arise.