Abstract: To enable multiple spawning events per year in yellow catfish (Pelteobagrus fulvidraco), we investigated the effects of temperature on gonadal development and reproduction. Under pond-culture conditions, annual water-temperature fluctuations were recorded and gonadal development in sexually mature males and females was compared. Under indoor culture conditions, a constant-temperature (CT, 25°C) group (set at the optimal breeding temperature) and an ambient-temperature (AT) group were established to compare year-round gonadal development, breeding performance, and spawning frequency in yellow catfish. During the first reproductive cycle, serum hormone levels and the expression of key genes involved in ovarian development were quantified. When pond water temperature stabilized at 25 ℃, females showed the highest proportion of stage IV oocytes, and sperm motility parameters reached their maxima. In the year-round trial, females in the CT group exhibited seven distinct peaks in gonadosomatic index (GSI), and males maintained relatively high GSI and sperm motility parameters throughout the year; by contrast, females in the AT group showed only two GSI peaks, and male GSI and sperm motility parameters remained high mainly during the natural breeding season. Artificial propagation further confirmed seven spawning events within one year in the CT group, with reproductive parameters remaining consistently high. The AT group spawned twice within one year, whereas reproductive performance in the second spawning event was significantly lower than that in the first. During the first reproductive cycle, serum estradiol (E₂) and vitellogenin (VTG) in the CT group peaked on days 15 and 30, respectively, whereas both increased gradually without a clear peak in the AT group. Quantitative real-time PCR showed that temporal expression patterns of pituitary fshβ, ovarian fshr, and hepatic esr1 and vtg1 were concordant with the serum VTG profile in both groups, whereas pituitary lhβ and ovarian lhr expression remained significantly higher in the CT group than in the AT group. Collectively, maintaining water temperature at 25°C promotes ovarian development and maturation, thereby enabling multiple spawning events per year in yellow catfish. This study alleviates the seasonal constraints on reproduction and provides a technical and mechanistic basis for off-season breeding in teleost fish.