We report the manipulation of magnetic anisotropy in a Co/Pt nano-multilayer (nano-ML) system with particles being embedded. The samples, fabricated by a newly-developed normal incidence pulsed laser deposition (NIPLD) method have salient magnetic characteristics, different from particle-free samples of almost the same structure: (1) they exhibit biaxial magnetic anisotropies and (2) there exists a critical field at which the change in easy direction from a parallel direction to a perpendicular direction and vice versa. By the careful manipulation of particles and nano-layers, we also demonstrate the control of the degree of magnetic anisotropy by embedding particles in a well-defined nano-ML system: uniaxial anisotropy to biaxial one and vice versa. This work, indeed, clearly shows that the integration of nano-building blocks into nano-structures can tailor properties of nano-materials. (C) 2002 Elsevier Science B.V. All rights reserved.