For much of the twentieth century, streets were designed to accommodate the ever increasing traffic flow, but it has become apparent that streets have many social and recreational functions which are severely impaired by fast car traffic. There is plenty of research on conditions for non-motorized transport and development of design measures on the streetscape to protect pedestrians and cyclists, but how places are made in the street is less studied and seldom implemented. In order to create more humanistic space in the street, we need to take consideration of people first, figure out how space can turn into a good place and which physical conditions will improve social life. This paper starts with pointing out the problems of ignoring social life in urban streets, and investigating the main theories and applications in contemporary western countries. After that, the thesis introduces literature on improving street life, including the books of Gehl: Cities for People (2010), New City Life (2006), and Burton and Mitchell: Inclusive Urban Design - Streets for life (2006), etc. Moreover, to see how these theories can be applied on a specific case, three streets in the town of Kristianstad are studied. This thesis is conducting an investigation on characteristics of these streets, observing social life in each street, and trying to figure out under which conditions does a street change from subduing social life to enhancing it. The theoretical tools and observation results of social life are all taken into the case study for practice, aiming at creating lively streets. My conclusions concern the primary factors for creating lively streets: location and role of the comparable streets in the overall traffic network, the characteristics of these streets and adjacent buildings, and the relationships between the physical conditions and the observed social life.