Bayaz Daraby - Academic member, Department of Mathematics, University of Maragheh, Maragheh, Iran,
Zahra Solimani - Ph. D. student, University of Maragheh, Maragheh, Iran,

In this article, firstly the notion of fuzzy orthonormality is introduced and then we establish celebrated Bessel‘s inequality in the sense that norm of space is Felbin rather than (B–S)-norm in fuzzy inner product spaces setups.

Orthonormal set, Bessel‘s inequality, Fuzzy inner product, Felbin-type fuzzy norm, Convergenity