House costs skyrocket that some residents are not affordable, so they are reluctantly expelled to another community. Furthermore, safety issue made by crime which is gangs’ dynamic activity in the conflict of gentrification. However, gentrification not only prospers the community, but also increase the public security. Because it could promote the economic growth of the nearby community and create more jobs for residents whose income is growing too, they can afford the rising rent of the house. In addition, gentrification also raises the patrol up and it exactly reduces the crime rate. For instance, Downtown L.A in the 90s had many insolent gangs that damaged the community ‘s harmony, but the gangs were controlled after gentrification. The crime rate in Downtown L.A has dropped continuously for eleven years. Gentrification makes cohesion between residents and immigrations and develops it into multiculturalism. It could be beneficial for a