Plipastatin A1 has been isolated from the culture of Bacillus cereus BMG302-fF67 and is an analog of plipastatins, acylpeptide inhibitors of phospholipase A2. It is a cyclic acyldecapeptide consisting of 3(R)-hydroxyhexadecanoic acid, L-Glu, D-Orn, L-Tyr, D-allo-Thr, L-Glu, D-Ala, L-Pro, L-Gln, D-Tyr and L-Ile, with a lactone linkage between the carboxyl of C-terminal L-Ile and the phenyl hydroxyl of L-Tyr. In this paper, the conformational model of plipastatin A1 is proposed by means of recent NMR techniques, high field NMR system, COSY and NOESY. The temperature dependence and hydrogen-deutrium exchange of amide protons are also studied. There are two β-turns formed from D-Orn to L-Tyr and L-Pro to L-Gln.