This paper reports findings from a survey of how rural junior secondary school students in the western part of China perceive their mathematics classroom learning environments and associations of learning environment with their attitudes toward mathematics and mathematics achievement. Using adaptations of the widely-used What Is Happening In this Class? questionnaire and a mathematics attitude scale, the study involved data from 749 Grade 7, 842 Grade 8 and 864 Grade 9 students from 12 coeducational schools and 52 classrooms in three provinces. Data were analysed through factor analysis, descriptive statistics, two-way ANOVA, simple correlation analysis and multiple regression analysis. It was found that rural junior secondary students generally did not perceive their mathematics classroom environment very favourably, and they did not hold very positive attitudes towards mathematics. There existed significant gender and grade differences in the perceptions of mathematics classroom learning environments and attitudes towards mathematics. Positive correlation between mathematics classroom learning environment and students' attitudes towards mathematics and their mathematics achievement were identified.