If one lives in the happiest city. I would be very happy. The criteria for selecting the happiest city include the living conditions and income of the residents. The state of the urban environment and the city's attractiveness of the three factors. First. One of the selection criteria of the happiest city is the living condition of the residents. Happiness comes from the heart, so one of the criteria for judging the happiest city is the living condition of its residents. This factor includes the residents' income, the residents' work and car living conditions and the residents' satisfaction with the city they live in and many other aspects. Only when the residents of the city are very satisfied with the city they live in. Only when the residents of the city are very satisfied with the city they live in, will the city become the happiest city. The second state of the urban environment is another important factor in judging the happiest city. Another important factor in judging the happiest city is the state of the city's environment. A city with the greatest sense of happiness. The city environment must be very superior. Whether it is the natural environment or transportation conditions, as well as education and health care and other aspects of the state should be very good. In order to meet the selection criteria of the happiest city. Third. The most important selection criterion for the happiest city is the city's attractiveness. The most important indicator of whether a city has a sense of happiness is the city's attractiveness. Only when a city has a very big attraction. All talents are willing to come to the city. The city can have a higher charm. Thus become the most happy city, in many of the criteria for judging the most happy city. This factor is the most critical. Only when a city has a strong attraction when he can become the most happy city.