||OBJECTIVES: The objective of this study was to examine the characteristics and distributions of possible SARS-CoV-2 target cells in the human TE and placenta. METHODS: Single-cell transcriptomic datasets of the early TE as well as the first- and second-trimester placentas have been reported1,2 . Here, we conducted the transcriptomic analysis of 4198 early TE cells, 1260 first-trimester placental cells and 189 EVTs at 24-week placentas (EVT_24W) by SMART-Seq2 method. Immunohistochemical staining of the human first-, second- and third- trimester placentas was performed to confirm bioinformatic results. RESULTS: Via bioinformatic analysis, we identified the existence of ACE2 and TMPRSS2 expression in human TE as well as in the first- and second- trimester placentas. In human TE data, 54.4% of TE1 cells, 9.0% of CTBs, 3.2% of EVTs and 29.5% of STBs were ACE2 positive. As for TMPRSS2, 90.7% of TE1 cells, 31.5% of CTBs, 22.1% of EVTs and 70.8% of STBs were TMPRSS2 positive. Amongst the placental cells, 20.4% of CTBs, 44.1% of STBs, 3.4% of EVT_8W and 63% of EVT_24W were ACE2 positive. And 1.6% of CTBs, 26.5% of STBs, 1.9% of EVT_8W and 20.1% of EVT_24W were TMPRSS2 positive. Pathway analysis revealed associations to morphogenesis of branching structure, extracellular matrix interaction, oxygen binding and antioxidant activity in ACE2+TMPRSS2+ EVT_24W cells. The ACE2+TMPRSS2+ TE1 cells were correlated with an increased capacity of viral invasion, epithelial cell proliferation and cell adhesion. Based on immunohistochemical results, expression level of ACE2 and TMPRSS2 in first- and second- and third-trimester placentas was observed. CONCLUSIONS: Our study has demonstrated the presence of ACE2 and TMPRSS2 positive cells in the human TE and placentas at different stages of pregnancy, which indicates the possibility that the SARS-CoV-2 could spread via the placenta and cause intrauterine fetal infection. This article is protected by copyright. All rights reserved.