We report the magnetic properties of aluminum nanoparticles (AlNPs) and composites of AlNP and silver nanoparticles (AgNPs). The AlNP powder was prepared by reducing aluminum oxide beads in pure water using high-repetition pulsed ablation method. An Nd:YAG pulsed laser with a wavelength of 1064 nm and a receptivity of 20 kHz was used for the ablation. From the results of SEM image and XRD measurements, the average particle diameter of the AlNP was 19 nm. The magnetic properties of the AlNP powder were measured by SQUID. The M-H curve showed superparamagnetism. But Pauli paramagnetic component was not found from M-T curve. In order to apply this AlNP powder as a solid material, it was mixed with silver paste and solidified by heat treatment. Note that it was confirmed that the AgNP obtained by drying the silver paste was weakly diamagnetic. The magnetic properties of the composite of AlNP and AgNP ((AlNP)/(AgNP)) showed interesting properties. Here, the number ratio of AlNPs and AgNPs in the composite material is expressed as (AlNP) x (AgNP) 1-x. Basically, the magnetic properties of the composite material were superparamagnetic. Although the magnitude of its saturation magnetization increased with the value of x, it did not increase monotonically but reached a maximum when x = 0.8. In the M-T curves of the composites, there was a paramagnetic component independent of the temperature. The value of this paramagnetic component was also not proportional to the value of x, and it was the maximum when x = 0.4. This result suggests that the paramagnetic component is not due to defects but Pauli paramagnetism. Even more surprisingly, hysteresis was observed in the M-H curve for the samples with x = 0.6 and 0.8, indicating that the samples are ferromagnetic material. Although the origin and mechanisms of the magnetic properties of these composite materials are under investigation, the experimental results show that the unique magnetic moment is induced in the composites and the existence of the magnetic exchange interaction inside the composites.