A series of boron aluminophosphate molecular sieves (BAPO-5) were synthesized by static hydrothermally method using the gel composition n(B ₂O ₃)/n(Al ₂O ₃)/ nP ₂O ₅)/ n(Et3N)/ n(H ₂O)=x∶y ∶1.5∶2∶240 . Based on the synthesized BAPO-5 molecular sieves, many of characterization was carried out by XRD, SEM, BET, FT-IR, MAS-NMR methods. It shows that the series of boron aluminophosphate molecular sieves with different boron contents are prepared in the[KG*4] range of 0＜ n(B ₂O ₃)/ n(Al ₂O ₃)＜0.08. And the crystal structure of BAPO-5 molecular sieves is attributed to the AFI structure type, which is the same as AlPO ₄-5. With the increase of the boron content, BET surface area and pore volume of BAPO-5 molecular sieves are also increased. This provides evidence of boron as heteroatom in the framework of BAPO-5 molecular sieves. It is observed that coordination environments of Al and P in the framework of BAPO-5 are AlO ₄ and PO ₄. Therefore, AlPO ₄-5 framework-incorporated B atoms brings no change of coordination environments of Al and P and structure type of BAPO-5 molecular sieves. In addition, SEM images show that the synthesized BAPO-5 molecular sieves have a regular hexagonal prism morphology. 