Yellow catfish (Pelteobagrus nitidus)is an important target species in Dianshan Lake fishery. From August 2011 to July 2012, 780 specimens of Pelteobagrus nitidus were sampled to study their biology.The results showed that: (1) The length distribution of yellow catfish samples was 4.7-16.0 cm, with a dominant group of 8.0-12.0 cm; The weight distribution of those samples was 1.3-28.4 g, with a dominant group of 5.0-15.0 g. (2) The mean length of females and males were 10.93 cm and 11.37 cm, with a mean weight of 15.1 g and 15.88 g, respectively. (3)The length-weight relationships of females and males were described as W_♀=0.041×L^2.533, and W_♂=0.037×L^2.557, respectively, and with significant difference based on covariance analysis. (4) The length of minimum sexual maturity of female and male yellow catfish were 8.6 cm and 9.4 cm respectively. (5) The mature individuals' gonad somatic index (GSI) of yellow catfish was obviously higher than the immature individuals' and the female immature individuals' GSI,which tended to increase with total length and conversely for the female mature individuals'. (6) The main prey of yellow catfish was shrimp and the feeding intensity was high in the classes 2 and 3 which accounted for 57.66% of the total specimens.