The paper suggests a possible model of the T-network of disturbance present inside the sample itself and points out the fact that another form of the T-network disturbance, the induction through electric field, may also cause a negative increment of tg δ reading. 本文提出了试样本身存在负损耗T形干扰网络的可能模型,同时指出了T形干扰网络的另一形式即空间电场感应也可以产生负损耗。