The Baogutu porphyry body I, II, V and VII (granodioritic and alaskite) intrude into the Lower Carboniferous volcanicsedimentary strata. Granodioritic porphyry can be divided into three types: fresh granodioritic porphyry, sericitedchlorited granodioritic porphyry and silicified granodioritic porphyry. They have similar HREE patterns but LREE differentiation is gradually strengthened. Compared with fresh samples, altered granodioritic porphyries are enriched in Rb, Th, U, Nb, Zr and Hf, and have lower Sr and Ti concentrations. Granodioritic porphyries have low initial 87Sr/86Sr ratio (0.70352 ~ 0.70365) and high 143Nd/144Nd ratio (0.512555 ~ 0.512635) indicating depleted mantle source. Porphyry body I and II were formed at a medium temperature (695 ~ 766℃) and low pressure (1.1 ~ 2.9kbr); the calculated oxygen fugacity for the porphyry bodies (ranging from -15 to -17) indicates that the fugacity gradually increased after rock formation. Oreforming element Cu was distinctively concentrated during sericitizationChloritization and silicification, suggesting constraint of hydrothermal process on mineralization.