A production method of raw coke materials for use in production of a carbon material for a negative electrode of a lithium ion secondary battery, comprising the step of: subjecting a heavy oil to coking in a delayed coking method, in which the ratio of the generation rate in mass% of a generated gas, which comprises C1-C4 gases and a hydrogen gas generated, to the formation rate in mass% of the raw coke materials, i.e. generation rate/formation rate, is from 0.3 to 0.8, characterized in that the delayed coking method comprises the step of: coking the heavy oil which is a mixture of desulfurized and deasphalted oil having a sulfur content of 0.05 to 0.40 mass% and RFCC bottom oil in a delayed coker under an inert gas atmosphere to obtain the raw coke materials which are a striped agglomerate having a semicircular sectional shape and having H/W of from 0.15 to 0.40 and L/W of 5.0 or more, wherein an average bow base of the cross section of the stripe is defined as W, an average bow height is defined as H, and an average length in the vertical direction is defined as L; and wherein the heavy oil is a first mixture consisting of 30 mass% of the desulfurized and deasphalted oil and 70 mass% of the RFCC bottom oil, or a second mixture consists of 70 mass% of the desulfurized and deasphalted oil and 30 mass% of the RFCC bottom oil, and when the heavy oil is the first mixture, a coking temperature is 465°C to 470°C, and a coking pressure is 500 kPa to 550 kPa, and when the heavy oil is the second mixture, a coking temperature is 470°C to 475°C, and a coking pressure is 500 kPa. subjecting a heavy oil to coking in a delayed coking method, in which the ratio of the generation rate in mass% of a generated gas, which comprises C1-C4 gases and a hydrogen gas generated, to the formation rate in mass% of the raw coke materials, i.e. generation rate/formation rate, is from 0.3 to 0.8, characterized in that the delayed coking method comprises the step of: coking the heavy oil which is a mixture of desulfurized and deasphalted oil having a sulfur content of 0.05 to 0.40 mass% and RFCC bottom oil in a delayed coker under an inert gas atmosphere to obtain the raw coke materials which are a striped agglomerate having a semicircular sectional shape and having H/W of from 0.15 to 0.40 and L/W of 5.0 or more, wherein an average bow base of the cross section of the stripe is defined as W, an average bow height is defined as H, and an average length in the vertical direction is defined as L; and wherein the heavy oil is a first mixture consisting of 30 mass% of the desulfurized and deasphalted oil and 70 mass% of the RFCC bottom oil, or a second mixture consists of 70 mass% of the desulfurized and deasphalted oil and 30 mass% of the RFCC bottom oil, and when the heavy oil is the first mixture, a coking temperature is 465°C to 470°C, and a coking pressure is 500 kPa to 550 kPa, and when the heavy oil is the second mixture, a coking temperature is 470°C to 475°C, and a coking pressure is 500 kPa. coking the heavy oil which is a mixture of desulfurized and deasphalted oil having a sulfur content of 0.05 to 0.40 mass% and RFCC bottom oil in a delayed coker under an inert gas atmosphere to obtain the raw coke materials which are a striped agglomerate having a semicircular sectional shape and having H/W of from 0.15 to 0.40 and L/W of 5.0 or more, wherein an average bow base of the cross section of the stripe is defined as W, an average bow height is defined as H, and an average length in the vertical direction is defined as L; and wherein the heavy oil is a first mixture consisting of 30 mass% of the desulfurized and deasphalted oil and 70 mass% of the RFCC bottom oil, or a second mixture consists of 70 mass% of the desulfurized and deasphalted oil and 30 mass% of the RFCC bottom oil, and when the heavy oil is the first mixture, a coking temperature is 465°C to 470°C, and a coking pressure is 500 kPa to 550 kPa, and when the heavy oil is the second mixture, a coking temperature is 470°C to 475°C, and a coking pressure is 500 kPa.