The taxonomy of cohesion devised by M. A. K. Halliday and R. Hasen was used to examine the kinds of cohesive ties used in argumentative prose written by 105 sixth, tenth, and twelfth grade students. In this way, the study sought to determine whether there were differences between grade levels in the kinds of ties used and in the numbers of subjects at each grade level using the various types of ties. Certain kinds of cohesion (substitution, ellipsis, temporal and continuative conjunctives) occurred infrequently at all three grade levels. There were significant differences among grades for four kinds of cohesion (same lexical item, other lexical items, long-distance ties, long-distance ties in the last three T-units), all occurring more frequently at higher grades than lower grades. There were no significant differences between grades in the number of students using a given kind of cohesive tie. (Tables of findings are included.) (RL)