There is a certain amount of bioelectricity existing in standing trees, which is expected to become a new supply of energy. But the power is very weak and it canÂÂt drive the existing low-power electrical equipment. In order to make use of this power reliably, we need to ascertain the variation and the influencing factors. Therefore, we measured the bioelectricity and environmental parameters of oriental plane and arborvitae for almost 3 months. The results show that the variation of potential difference between the soil and the standing tree is cyclical and is low in daytime and high in night. Meantime, we found that standing treeÂÂs bioelectricity is significantly associated with the ambient temperature, humidity and other parameters. The content of standing treeÂÂs sap is possibly an important influencing factor to its bioelectricity.