Abstract：Improving health care in later life is crucial, especially under the impact of world population ageing. It provides challenges and opportunities for health and ageing research, and global co-operations and joint commitments among different countries are needed. Supported by the Canada-China Joint Health Research Initiative Program, the Canada China Study in Ageing and Longevity is the first research of the kind to compare the process of ageing and health changes between Canadian and Chinese. The collaboration sets up a data and knowledge sharing agreement between the participate partners. The initial proposal was for the " Quantification of health status changes in China and in Canada: an evaluation of a stochastic model of health transition". As the project evolves, however, the focus is expanding to develop a quantative method to assess frailty in elderly Chinese people, corresponding to information collected in Canada in Comprehensive Geriatric Assessments (CGAs). The Canadian team has established the Frailty Index and a stochastic ageing model, which despite mathematically simplicity, can capture characteristic health statue changes. The model will be applied to study Chinese datasets and parameters will be compared between different countries. In additional, a new version of the Frailty Index, based on a CGA (the FI-CGA) will be developed, tested and modeled. Through various research activities, the collaborative research will allow quantification not only of the impact of ageing, but also of the impact of a feasible intervention on improving public health in different social settings. Keywords：Ageing;Canada-China Health Research Initiative Program;Frailty;Health