The world has become increasingly interdependent with the ongoing trend of globalization. Preparation for citizenship obviously needs to extend beyond students’ national boundary, such as understanding the impact of citizenship behaviors in one region upon the other parts of the world, and the promotion of peace and justice across nations. This paper reports a study on global citizenship education (GCE) in secondary schools in Hong Kong and Shanghai conducted from December 2002 to June 2003, organized by the Centre for Citizenship Education of the Hong Kong Institute of Education, the Department of Education of the Shanghai Teachers' University, and the Love Outreach Education Academy and Oxfam Hong Kong, with funding provided by the latter. The study aimed at understanding (1) teachers’ knowledge, skills and values toward GCE, (2) GCE curriculum available in schools and its implementation; (3) difficulties in implementing GCE in schools; and (4) the kind of change and support that teachers expected for enhancing the development of GCE. The study also provided data for comparing the similarities and differences in the two major international cities in China. The study finds that that teachers in Hong Kong and Shanghai both support global citizenship education in their schools, but they have encountered problems and difficulties such as pressure from the exam-oriented curriculum, lack of training, lack of support from the school and government, and also a lack in self-efficacy, not feeling that personal efforts can bring about changes in the world. There are interesting contrasts between Hong Kong and Shanghai teachers. Shanghai teachers are comparatively more interested in global affairs, whereas Hong Kong teachers are relatively more interested in local affairs. Shanghai teachers tend to focus on knowledge and skills in global citizenship education, whereas Hong Kong teachers tend to focus on values.