Moulting is an essential process for the survival of birds. Moulting strategy is related to bird evolution, and adaption. The moulting strategy of two wren warbler species (Prinia flaviventris) and Plain Prinia (P. inornata) was studied. Samples were collected by mist net at Jiangxi village, Zhaoqing, Guangdong, China, from March to September, 2007.The measurements of body mass and feather characteristics were taken. The primary feathers were numbered one by one from the outermost (P1) to the innermost (P10), secondary feathers were numbered from the middle (S1) to the innermost (S9), and the tail feathers were numbered from the middle (T1) to each side (T5). The body mass difference between months was performed by one way ANOVA, Pearson correlation was employed to analyze the partial correlation between tail length and tail width (body length as the control variable). Our study found out 1) the two species of wren warbler started to partially change their body feather in March and ended in May within 60 days; 2) their tail feather was completely replaced in spring from the inner pair to the outward one (Fig. 1); 3) the tail length and tail width of the two wren warbler species changed synchronously (Table 1), and the ratio of tail length in the non-breeding season to that in breeding season was larger than the ratio of tail width in the non-breeding season to that in breeding season (Table 2), indicating the tail was broader in breeding season; 4) there was a trend that the two species reduced their body mass during mounting period although with no significant difference (P > 0.05). We presumed that the two wren warbler species would increase their food intake to compensate the energy requirement in the period of breeding and moulting simultaneously occurred. This behavior may indicated that the moult strategy is an adaption to their habitat in which can provide rich food resource.