Both in-situ and ex-situ giant pandas (Ailuropoda melanoleuca), display shifts in bamboo species and part preference throughout the year. The effects of this shifting preference on gastrointestinal (GIT) microbiota were observed using traditional culturing methods to characterize normal GIT microflora from fecal samples and behavioral feeding data of adult male and female pandas over a fourteen-month period. Linear and quadratic fits were used to determine any significant relationships between the time of year and part preference on the GIT microflora (P<0.05). Significant values for time of year were observed with the linear fit in total aerobes (P-value=0.0368), streptococci (P-value=0.0120), and lactobacilli (P-value=0.0166) and quadratic fits in streptococci (P-value=0.0382) and Bacteroides spp. (P-value=0.0134) at á=0.05. Significant linear relationships were observed with part preference and lactobacilli and Bacteroides spp., P-values of 0.0028 and 0.0030, respectively, indicating that part preference and time of year may affect the flux of panda GIT microflora.