The purpose of this study was to develop and validate a series of the ¡§Gender Stereotype Threat Inventory¡¨(GSTI) of junior high school students in science classroom. The GSTI was included three scales: domain indentification, gender stereotype and learning environment. The GSTI was conducted to a total of 640 8th graders in Kaohsiung city. Results of the study were employed for internal consistency analysis, confirmatory factor analysis, Rasch modeling analysis, as well as the multiple invariance approach to test its reliability and validity. The result manifested that each scale had reasonable coefficient Cronbach alpha ranging from .73 to .85 and the overall model fit indices indicated that model fitted the oberserved data and had cross-validation. Finally, the results of gender stereotype threat in science classroom and implications for using the GSTI inventory in future research are presented.