Aims:In this study, we prepared spirulina polysaccharides into spirulina polysaccharide-loaded nanoemulsions (SPS-NEs), and determined the antitumor effect of SPS-NEs, when combined with paclitaxel (PTX). Methods:SPS-NEs were prepared by a phase transformation method. The Characterisation and stability of SPS-NEs was measured. The antitumor effect of SPS-NEs combined with PTX was determined by S180 cells or RAW 264.7 macrophages and S180 tumour-bearing mice. Results:SPS-NEs were spherical and stable, the particle size of SPS-NEs was 84.6 +/- 3.31 nm, PDI = 0.235 +/- 0.02. PTX + SPS-NEs exhibited a much greater toxicity against RAW 264.7 cells than PTX. PTX + SPS-NEs increased the release of NO, IL-6 and TNF-alpha, and the expression of p-p65 NF-kappa B, p-I-kappa B, TLR4. In addition, PTX + SPS-NEs significantly inhibited tumour growth by 72.82% and increased the secretion of serum IL-2, TNF-alpha and IFN-gamma. Conclusions:SPS-NEs can regulate immunity through TLR4/NF-kappa B signalling pathways, which enhances the anti-tumour effect of PTX.