The evaluation of the hydrocarbon generation potential for the Proterozoic-Paleozoic marine source rocks with the highly maturity to over-maturity in the Chinese marine sediment basins has been much disputed, due to the absence of the applicable evaluation criteria and method. The geochemical analysis data reveals that there are distinctive linear relations between the total organic carbon content (TOC) and generation potential of different types of immature or low-mature Proterozoic-Paleozoic marine source rocks. The lowest TOC threshold for the marine carbonate as an effective potential source rock, must be greater than 0.5%, and has no essential dissimilarity from the marine shale or mudstone. The source rock with TOC less than 0.75% is poor of hydrocarbon potential for the Proterozoic to the Lower Paleozoic marine source rocks, and TOC 0.75%~1.5%, fair; 1.5~2.0%, good; 2~4%, very good; >4%, excellent. The TOC limit of each level for the Upper Paleozoic shale is slightly higher than that of the Lower Paleozoic shale. The initial potential of source rocks with highly or over-maturity in the Chinese Proterozoic-Paleozoic marine sediment basins can be calculated by its TOC and the equations obtained from the immature or low-mature marine source rocks.