The Chinese Language Classroom Environment Inventory (CLCEI) is a bilingual instrument developed for use in measuring students' and teachers' perceptions toward their Chinese Language classroom learning environments in Singapore secondary schools. The English version of the CLCEI was customised from the English version of the "What is happening in this class? (WIHIC)" questionnaire (Fraser, Fisher, & McRobbie, 1996) and its Chinese version was modified from the Taiwanese Chinese version of the WIHIC questionnaire (Huang & Fraser, 1997). The CLCEI consists of six 8-item scales examining 6 different dimensions of the Chinese language classroom learning environments, namely, "Student Cohesiveness, Teacher Support, Involvement, Cooperation, Task Orientation and Equity". It was validated with a sample of 1460 secondary three (grade 9) students from 50 express stream (above average academic ability) classes in 25 secondary schools in Singapore. Various statistical procedures were undertaken to examine the factor structure, validity and reliability of the scales of the CLCEI. The validation results indicated that each of the scales exhibited high internal consistency reliability and satisfactory discriminant and factorial validity. The validation results also indicated that each scale of the CLCEI had the ability to differentiate between perceptions of students from different Chinese language classes. (Contains 4 tables.)