Abstract: The goal of an overall well-off society cannot be achieved without the health of all people. Building a top-level public health system would be the best choice as China is faced with more challenges on the way to "health for all people". Supported by the Fourth Round of the Three-Year Public Health Action Plan in Shanghai (2015-2017), this study has brought together experts from governments, universities, institutes and agencies to conduct research on the theoretical and practical issues on building a top-level public health system. The achievements were as follows: (1) What is Public Health was defined, with the approval rate of 97.6%-99.2%. (2) The definition of Public Health System was clarified, with the approval rate of 99.1%. (3) The public health issues which all governments should pay attention to were demonstrated, including 11 categories, 48 sub-categories and 222 specific issues, with the approval rate of 88.2%-100.0%. (4) What a top-level public health system should be was illustrated, including 8 elements and 63 characteristics, with the approval rate of 88.8%-93.9%. (5) The assessment criteria consisting of 83 indicators were designed, with the approval rate of 94.1%-100.0%, which was used to evaluate the extent to which the public health system has achieved. (6) The advantages and strategies in the public health system of Shanghai were demonstrated. Shanghai's public health system has achieved obvious improvements with the great emphasis of the governments. The performance score of Shanghai was 15.9% higher than that of New York, while there remained a 27.3% gap in being top-level. Future challenges include establishing a coordination mechanism with clarity responsibilities, improving a sound resource allocation mechanism, and retaining a stable, competent, incentive public health workforce.