To understand the fishery biology of Symbolphorus californensis, the age and growth were analyzed in 175 samples collected in the high seas of Northwest Pacific Ocean from June to July 2022 through the observation of otolith microstructure. The results showed that the sagittal otolith of S. californensis is elliptical, with a sinuate dorsal margin, shallow sulcus, and rounded to oval cauda. The otolith microstructure along sagittal section exhibited three of the growth zones： CZ, MZ and EZ, respectively with 45-50、38-45 and 157-465 daily growth increments. The sum of daily growth increments in the three zones determined an age range （lifespan） of S. californensis specimens as 242-550 days, with the dominant group from 301 days to 400 days （91.46%）. By obtaining the age in days of each specimen, the back-calculated hatching date of specimens collected was determined as from March to August of last year with a peak in May to June. The AIC analysis indicates that the optimal growth equation is the von Bertalanffy growth model, with the fitting as： L_t=146.325×｛1-exp[-0.01×（t-229.392）]｝.In addition, S. californensis of Northwest Pacific Ocean was found to have daily growth increments of its sagittal otolith, which also exhibited lunar periodicity in the deposition of increments, with growth increments during the full moon period. The results of this study reveal its life history characteristics and provide scientific basis for future resource utilization.