Tetraphenylethylene (TPE) derivatives [(RPhCH=CHPh)PhC=CPh(PhCH=CHPhR), R = H, CN, NO₂, NPh₂] with green, yellow-green and orange emission colors are designed and synthesized.  These TPE derivatives are strong luminophors when aggregated, although they are virtually nonemissive in dilute solutions.  When blended with poly(methyl methacrylate), the resultant TPE/PMMA films exhibit bright emissions.  Restriction of intramolecular rotations in the aggregative or solid states may be responsible for the novel "aggregation-induced emission" effect.  Further modification of their molecular structures may generate new materials with desired attributes that can find an array of applications in optical display and biological probe systems.