The present invention provides a new method of determination of volcanic rock layering marks. The method provided by the invention comprises: performing GR logging aiming at an object volcanic rock interval, and obtaining a GR curve of the object interval; eliminating abnormally high values and abnormally low values in the GR curve based on the available research data; finding out the maximum value GRmax and the minimum value GRmin of the GR of the object interval in the processed GR curve, defining the maximum value GRmax and the minimum value GRmin as the environmental critical level of the GR of the object interval, and calculating an environmental factor [Delta]; drawing a curve chart through the environmental factor [Delta], lining out the baseline of the [Delta] curve in the curve chart, and dividing the curve into different typical regions according to the relative position relation of the [Delta] curve and the baseline through the overall observation, the curve breaks at the cutting line being layering marks, with respect to different rock stratums, between different rock stratums. According to the new method of determination of volcanic rock layering marks, the influence of human factors may be substantially reduced so that GR values in the regions may be unified onto the same comparing platform; and moreover, the accuracy of the layering may be improved, the determination time of the layering may be reduced, and the research cost may be decreased.