We introduce a pre-Jacobi-Jordan algebras and study some relevant properties such as bimodules, matched pairs. Besides, we established a pre-Jacobi-Jordan algebra built as a direct sum of a given pre-Jacobi-Jordan algebra (A, •) and its dual (A * , •), endowed with a non-degenerate symmetric bilinear form B, where • and • are the products defined on A and A * , respectively. Finally, after pre-Jacobi-Jordan algebras classification in dimension two, we thoroughly give some double constructions of pre-Jacobi-Jordan algebraic structures. Keywords. (pre)Jacobi-Jordan algebra, bimodule, matched pair, double construction MSC2010. 16T25, 05C25, 16S99, 16Z05.Preprint: ICMPA-UL/2019/12 Definition 2.4. [13] A vector space V is a module over a JJ algebra A, if there is a linear map (a representation) ρ : A → End(V ) such that ρ(x ⋄ y)(v) = −ρ(x)(ρ(y)v) − ρ(y)(ρ(x)v)(2.4)for any x, y ∈ A and v ∈ V .