The shortage of open spaces in developing countries in Asia such as Vietnam has been a thorny question for urbanists. Due to a poor history of public spaces, people tend to use street spaces as open spaces and other functions that bring chaos and danger onto the streets. Although developed countries in the West have overcome the dangers of life on street spaces to some extent, Vietnam, with its low quality of life, retains its inherent street bustle. Street improvements have been carried out to enhance the quality of urban life. This research aims at comparing improved and unimproved street spaces in various aspects, including user behavior and the environment-behavior relationship within street spaces and their surroundings. The findings contribute to the future improvement of street spaces in Vietnam and other developing countries based on theories of Environment-Behavior Studies. Through this research, the street renovation and development idea can be processed in a distinctive manner that appreciates the cultural and social context instead of being derived from the arbitrary or intuitive ideas of designers. By using various observation methods such as centered behavioral mapping (PcBM) and visual encounter surveys (VES), and statistical analysis such as principal component analysis (PCA) and cluster analysis (CA), the findings show that a total of eight physical attributes need consideration during street renovations or development processes. Improved and unimproved street spaces share two attributes and differ in six attributes. Additionally, three environment-behavior patterns support the implications detailed in this paper. Finally, a suggestion for street space development and management is made to support related authorities and urbanists in future projects; it is hope that this research will contribute to creating more livable and sustainable street environments.