358 and 522 specimens of Acrossocheilus parallens were collected from July 2007 to June 2009 in the middle and upper reaches of Beijiang River and the upstream area of Liuxihe River, respectively. These specimens were used for the comparative study on reproductive characteristics of these neighboring populations. The scales were collected and used for age determination, the total length, standard length, total weight, net body weight and ovary weight were measured, and the gonadosomatic index and the fullness were calculated. The results showed that the age of reproductive population we collected in from 1 to 5 for female, and 1 to 4 for male in Beijiang River population, and the sex ratio of female to male in the reproductive population is 1:1.73. The corresponding number was 1 to 4 for female, and 1 to 3 for male in Liuxihe River population, with the sex ratio of female to male in the reproductive population is 1:1.40. For different age groups, both standard length and total weight of the reproductive population of Beijiang River were significantly larger than Liuxihe River population. The Beijiang River population have longer spawning period than the Liuxihe Population: the spawning period of A. parallens in the Beijiang River population was from January to October, mainly in March to July, while the population of Liuxihe River population was from January to August, mainly in May to July. In the spawning period, for both of female and male of Beijiang River population, the gonadosomatic indices were higher than the Liuxihe population. All of the individual absolute fecundity (F), the individual relative fecundity of standard length (FL) and the individual relative fecundity of total weight (FW) of the Beijiang River population, were significantly higher than that of the Liuxihe population. All the distinction between the populations of Beijiang River and Liuxihe River were analyzed with the nutrient status, fishing intensity, and the stream order.