The effects of fuel properties on white smoke emission from the latest DI diesel engine were investigated with a new type of white smoke meter. The new smoke meter could distinguish fuel effects on smoke much more than the conventional PHS meter. The repeatability of the smoke meter was better than that of the PHS meter. Cetane number was the dominant factor for smoke emission. Distillation temperature and composition also affected emission. A nitrate type cetane improver was effective for reducing emission. White smoke was analyzed with GC and HPLC and compounds in white smoke from low cetane number fuel were found almost the same as in fuel. But those from high cetane number fuel consisted of compounds in fuel and many combustion products.