The adsorption of a polymer chain on an attractive nano-sized spherical particle is studied by using Monte Carlo simulation. The polymer-particle interaction is treated as Lennard-Jones potential with strength e PP. The critical adsorption point e * PP is estimated from the largest fluctuation of the number of monomers contacted with particle. We find that e * PP is dependent on the comparison between particle size σ p and R G0, the mean radius of gyration of polymer in dilute solution. e * PP decreases with an increase in σ p at σ p < R G0 and is independent of σ p at σ p ≥ R G0. The polymer starts to be adsorbed on particle, and the mean contact time begins to increase at e * PP. In addition, the structural property characterized by trains, loops, and tails is investigated for polymer contacted with particle. Results show that the structure is dependent on the interaction strength e pp. We find that both the number of monomers contacted with the particle and the length of trains increase with e pp, whereas lengths of tail and loop decrease with the increase in e pp.