在制作扫描电镜样品时，通常要求样品新鲜，在戊二醛中固定的时间不宜太长。但本文制作的人蛔虫样品已在福尔马林中浸泡了４０年，猪蛔虫样品也在甘油和７０％酒精（１∶１９）中浸泡了１年多时间，制作后发现与新鲜样品一样，表面干净，没变形，没萎缩。 In the production of SEM samples, the sample is usually required fresh, in glutaraldehyde fixed time should not be too long. However, the human roundworm sample prepared in this article has been soaked in formalin for 40 years. The swine Ascaris samples were also soaked in glycerol and 70% alcohol (1:19) for more than one year. The samples were found to be as clean as fresh samples , No deformation, no atrophy.