Infant is the most vulnerable groupof safer infectious diseases caused by complementary food. Meanwhile complementary food safety was unknown. The study aimed to know Escheriacoli (E. coli) contamination in serving complementary food and relationship of house sanitation condition as clean water facilities, places for dishes infant food utensils,domestic wastewater facilities condition, garbage facilities condition and the present of domestic animals in houseto E. coli contaminationin serving. Study design was cross sectional, object of observation were 138 household that serving complementary food for 6-12 month old infants. Location of study was in 21 subvilages at Solok District. Data analysis was used to know description of E. coli contamination, household sanitation condition, relationship between household sanitation factor with E. coli contamination and the most significant sanitation factors that have relationship with that contamination. This study found (72.5%) serving complementary food have been contaminated by E. coli. The domestic animals in the house, 2 times more risks to have E. coli contimination in complementary serving.