Abstract: Water-based suspension of submicron Sb₂O₃ was prepared, and then modified with polyvinyl alcohol (PVA) as a steric stabilizer, the modified Sb₂O₃ was composed with chloroprene latex (CRL) for preparing the flame retardant latex composite (Sb₂O₃-PVA/CRL). The modification parameters and their influences on dispersion stability were investigated. The mechanism of the improved dispersion stability produced with PVA interface modification was estimated in terms of distribution of particle size, FTIR and DTA-TGA analysis. The results show that the grinding of mortar is an effective means of preparing the submicron Sb₂O₃ via micronization action. The stretching vibration peak of -OH groups being weaker at 3 447 cm^-1and the peak of C-O groups disappearing at 1 091 cm^-1 in the FTIR spectra of Sb₂O₃ modified with PVA, concluding that the chemical-bonding plays an important role in the modification. The optimum modification parameters of the best dispersion stability are PVA to Sb₂O₃ mass ratio of 2%, reaction temperature of 90℃ and reaction time of 30 min. The suspension of Sb₂O₃-PVA/CRL has good dispersion stability when it has been stored for 6 h.