The quick and accurate determination of the hydrocarbon accumulation time and period is of great significance to understanding the mechanism and distribution rules of this process. As a marker of the hydrocarbon accumulation, bitumen is an important factor in the analysis of hydrocarbon migration path and the exact time of its accumulation. This article was based on systematic research on the Raman spectroscopy of bitumen in the Yangshuiwu buried hill reservoir. The bitumen in this reservoir is mainly distributed in the later formed cracks, and few are filled in the pores. Bitumen almost has no fluoresce under ultraviolet light, so it can be catalogued to carbonaceous bitumen. The experimental results show that the bitumen in this area has relatively stable Raman spectrum characteristics, with obvious D-peak and G-peak that do not change from different test points in the same stratum. However, the background noises may be changed at a different point. The Raman spectrum goes up after 1 500 cm^-1. When processing the Raman spectrum data, the background value was subtracted from the original data firstly, and then the Lorentz peak-differentiation method was used to fitting the peaks, until the fitted spectrogram curve is basically consistent with the original shape. The peak height (H) of D-peak and G-peak, the full width at half maximum (FWHM), the distance between D and G, the lowest value between D-peak and G-peak and other parameters were obtained directly from the fitted curve. Saddle index can be calculated by these parameters, and the bitumen maturity was also calculated by the formula. The results of the calculation indicate that the reservoir bitumen is heterogeneous, which means the oil is multi-sourced. The bitumen maturity parameters are mainly distributed in two areas, with R_o=1.00~1.37 and R_o=1.44~1.94, respectively. Combined the bitumen maturity parameters with the burial history to determine the Yangshuiwu buried hill hydrocarbon accumulation time, two periods of accumulation were confirmed, condensate and moisture gas accumulation stage of Dongying period (35~25 Ma) and natural gas charging stage of Minghuazhen-present (5 Ma~0). Results are consistent with the hydrocarbon generation history of the source rocks in the study area. This study shows that Raman spectroscopy can perform micro-analysis of bitumen in different positions in the reservoir, obtain high-precision spectral data, and then calculate the maturity of bitumen accurately. Therefore, quantitative characterization of reservoir bitumen Raman spectrum and quantitative calculation of maturity, combined with simulation of basin burial and thermal history, the exact time and period of hydrocarbon accumulation can be determined. This method is fast, accurate and inexpensive, therefore has a promising application prospect.