Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a extremely infectious disease, and the current outbreak has been declared by WHO as a global public health threatening. Researches have showed that transmission of SARS-CoV-2 is mainly from person to person via airborne droplets. It is unclear whether SARS-CoV-2 can be shed into human milk and transmitted to a child via breastfeeding. Here we investigated SARS-CoV-2 RNA in breast-milk samples of three mothers with SARS-CoV-2 and their infant. The human milk sample of one mother for SARS-CoV-2 RNA was positive. By contrast, SARS-CoV-2 RNA was not detected in human milk of two mothers.The throat swab sample was also positive in the infant of the mother whose SARS-CoV-2 RNA was detected in human milk. By contrast, throat swab of others infants was negative. Because the mother with SARS-CoV-2 RNA detected in human milk sample is not breastfeeding, the risk of contagion from the infant to the mother is eliminated. To date, in the literature, the presence of SARS-CoV-2 RNA has only been detected in the breast milk of two mothers with SARS-CoV-2. To the best of our knowledge, our case is third case with SARS-CoV-2 RNA detected in human milk. On the other hand, this is first case with SARS-CoV-2 RNA detected in human milk of mother who does not breastfeed her infant.The existing data indicates that SARS-CoV-2 can be rare transmitted through human milk.