Breastmilk donors are increasingly widespread and can be done by mothers easily and rapidly through the internet. This study aims to analyze the correlation of knowledge and attitudes of breastmilk donors to the behavior of breastmilk donors via the internet in Indonesia. The study used a cross-sectional analytic design and using a total sampling technique by sending research instruments in the form of the Google form was conducted in January-April 2017. The study respondents were breastmilk donors who posted information on their breastmilk to be shared through Facebook Human Milk 4 Human Babies Indonesia in Jakarta, Depok, Indramayu, Bandung, and others were totaling 41 respondents. Statistical analysis using the Spearman test with confidence level was α=0.05. The study results showed that the correlation to knowledge and behavior of breastmilk donors had p value=0.080, while the correlation on attitude and behavior of breastmilk donors had p value=0.715. In conclusion, there was no correlation between the attitude of breastmilk donors and the practice of breastmilk sharing via the internet.