Synthesis and optical properties of cocoon-like poly(methyl methacrylate) (CPM) particles in the size range of D (n) = 3.0-6.5 mu m were studied. The synthesis of these anisotropic particles consists of two steps. The spherical poly(methyl methacrylate) (PMA) particles (D (n) = 2.2-5.5 mu m) cross-linked by 0.2-0.8 wt% ethylene glycol dimethacrylate (EGDMA) were prepared by dispersion polymerization, using a combination of poly(vinyl pyrrolidone) (PVP) and sodium di-(2-ethylhexyl) sulfosuccinate (NaEHS) as a stabilizer in 94:840 water-methanol. Then, a suspension polymerization of 9:1 methyl methacrylate (MMA)/EGDMA in the presence of the PMA particles as seed at 85 A degrees C in water gave non-spherical, cocoon-like CPM particles, depending on the cross-linking densities of PMA particles. The cocoon-like CPM particles (D (n,c) = 4.0 mu m) showed the characteristic features of regular reflection, which can not be attained for conventional poly(methyl methacrylate) particles with a spherical shape. The effects of seed PMA particles with different properties on the formation of cocoon-like CPM particles and their regular reflection properties are described.