Title : The factors Related to The Sanitation Practice through Clean and Healthy Life Behaviour on Elementary School Students at Banyumanik DistrictBackground: The high rate of diarrhea incident in Semarang, especially on elementary school students, needs a special attention. The incident rate in the area of Banyumanik district shows a high level compared to those of other working areas. The incident rate of 5-14 year ages shows an increase from 2013 to 2015, from 142 to 187 and to 289 cases. Clean and healthy environment sanitation through “PHBS” seems to be the simple way to a self protection against various diseases. Based on the - background mentioned above, the research was conducted to analyze the factors relating to the sanitation practice of clean and healthy environment through “PHBS”. Method: This research was conducted by using descriptive analysis with a quantitative approach. The research samples were taken using random sampling of 72 elementary school students from 11 elementary schools at Banyumanik district. Results: The research result showed that 68,1% of the respondents experienced a good practice and 31,9% experienced a not-so-good practice. The statistical analysis showed that there was a correlation between knowledge of clean and healthy sanitation environment (p-value = 0,019) and attitude (p-value = 0,029) toward the practice of clean and healthy sanitation environment.Conclusion: Level of knowledge was able to increase attitude toward practice of clean and healthy sanitation environment.