This study was performed to investigate improving immune activities of natural water-soluble sulforaphane extracted from Brassica oleracea var. italica by nano encapsulation process. The nanoparticles of the sulforaphane extracted with ultrasonification process at $60^{circ}C$ promoted human B and T cell growth, about $7{sim}35%$ compared to the control. The secretion of IL-6 and TNF-${alpha}$ from T cells were also enhanced as $2.6{ imes}10^{-4}pg/cell$ and $2.1{ imes}10^{-4} pg/cell$, respectively, by the adding nano samples. NK cell activation was improved about 8%, compare to the control in adding cultured medium of T cell added nano samples. It was also found that sulforaphane extracted from B. oleracea var. italica had highly inhibitory activity on hyaluronidase as $IC_{50}$ about $200;{mu}g/m{ell}$. It can be concluded that natural water-soluble sulforaphane samples by nano-encapsulation, each size is 200 nm, extracted from B. oleracea var. italica has high immune activities through higher efficiency of bio-activation than conventional extracts.