The purpose of this dissertation is to investigate gender differences in mathematics cross culturally (Japan and the United States), and to find whether there are gender differences in their sex-stereotyped beliefs about mathematics, attitudes toward mathematics, learning patterns of mathematics, and problem solving strategics/ causes of mistakes and whether there are relationships among these variables. There were 2 studies. In Study 1, two performance variables, efficiency of problem solving strategics and seriousness of causes of mistakes, were developed through protocol analysis. In Study 2 , 207 10th grade Japanese high school students and 164 9th to 12th grade American high school students participated. Subjects were administered (1) 5 SAT-Math items, (2) solution strategy and causes of mistake questionnaire, (3) attitude toward mathematics questionnaire, and (4) learning patterns questionnaire. A 2 (sex) x 2 (nation) analysis of variance and separate within nation univariate analysis by gender were performed on the 12 variables, 3 in each of 4 areas (sex-stereotyped beliefs about math, other attitudes toward math, learning pattern of math, and performance). For Japanese sample, moderate to large gender differences were found in the sex-stereotyping and attitude variables. For the U.S. sample, gender differences were found in sex-stereotyping variables were opposite for the Japanese sample and for the American sample. Among the American sample, females held more egalitarian views toward mathematics than males. in contrast, in the Japanese sample, it is the females who held stronger sex-stereotyped beliefs about mathematics than males. Regardless of students' nationality, there were significant relationships between attitude variables and learning variables.