This paper presents a new kind of splines, called non-uniform algebraic-trigonometric B-splines (NUAT B-splines), generated over the space spanned by {1,t,...,tk-3,cost,sint} in which k is an arbitrary integer larger than or equal to 3. We show that the NUAT B-splines share most properties of the usual polynomial B-splines. The subdivision formulae of this new kind of curves are given. The generation of tensor product surfaces by these new splines is straightforward. 2003 Published by Elsevier B.V.