The common harmful residues found in animal specimens are mainly due to taxidermy, conservation and the environment. In order to clarify the situation, Guangdong Museum (GDM) used energy dispersive X-ray fluorescence (ED-XRF) and inductively coupled plasma-optical emission spectrometry (ICP-OES) for analysis and then found that 1) both feather and hair of specimens in GDM contain sulfur (S), calcium (Ca), arsenic (As), chlorine (Cl), potassium (K), aluminum (Al), iron (Fe), silicon (Si) and zinc (Zn), etc. using ED-XRF to detect elemental compositions; and 2) mammalian and large raptor specimens have higher amounts of trace elements such as iron and zinc. Under normal conditions, arsenic, which is toxic, adheres to the surface and inside of specimens for a long time, affecting both keepers and the environment. Thus, it is recommended that arsenic compounds be prohibited in taxidermy.