A hot-rolled steel sheet for an electric resistance welded steel pipe having excellent expandability, comprising: 0.15 wt% to 0.22 wt% of carbon (C), 0.1 wt% to 1.0 wt% of silicon (Si), 0.8 wt% to 1.8 wt% of manganese (Mn), 0.001 wt% to 0.03 wt% of phosphorus (P), 0.001 wt% to 0.01 wt% of sulfur (S), 0.001 wt% to 0.19 wt% of soluble aluminum (Sol.Al), 0.3 wt% to 1.0 wt% of chromium (Cr), 0.01 wt% to 0.05 wt% of titanium (Ti), 0.025 wt% or less of niobium (Nb), 0.035 wt% or less of vanadium (V), 0.001 wt% to 0.01 wt% of nitrogen (N), and a balance of iron (Fe) and other inevitable impurities, wherein the Mn and Si satisfy the following Relational Expression 1, wherein a microstructure comprises a ferrite phase in an area fraction of 60 to 80% as a matrix structure and a hard phase composed of martensite and bainite phases, wherein a fraction of grains in which the martensite phase and the bainite phase are mixed in a single grain of an entire fraction (area fraction) of the hard phase is 50% or more, and a carbon distribution in the grain satisfies the following Relational Expression 2, wherein the hot-rolled steel sheet has a tensile strength (TS) of 980MPa or more, and a yield ratio (YR = YS / TS) of 0.8 or less, wherein an expansion ratio of the pipe is 85% or more compared to an elongation of the hot-rolled steel sheet after pipemaking the hot-rolled steel sheet, wherein the parameters are measured according to the description. 4 < Mn/Si < 12 where, Mn and Si mean the weight content of each element, 1.2 ≤ P CB / P CC ≤ 2.0 where, PCB means a measure value of EPMA intensity of carbon at 70% point of a distance from a center of the grain in which the martensite and bainite phases are mixed in the hard phase to a boundary of the grain, and PCC means a measurement value of the EPMA intensity of carbon at a central point of the same grain, measured according to the description. 0.15 wt% to 0.22 wt% of carbon (C), 0.1 wt% to 1.0 wt% of silicon (Si), 0.8 wt% to 1.8 wt% of manganese (Mn), 0.001 wt% to 0.03 wt% of phosphorus (P), 0.001 wt% to 0.01 wt% of sulfur (S), 0.001 wt% to 0.19 wt% of soluble aluminum (Sol.Al), 0.3 wt% to 1.0 wt% of chromium (Cr), 0.01 wt% to 0.05 wt% of titanium (Ti), 0.025 wt% or less of niobium (Nb), 0.035 wt% or less of vanadium (V), 0.001 wt% to 0.01 wt% of nitrogen (N), and a balance of iron (Fe) and other inevitable impurities, wherein the Mn and Si satisfy the following Relational Expression 1, wherein a microstructure comprises a ferrite phase in an area fraction of 60 to 80% as a matrix structure and a hard phase composed of martensite and bainite phases, wherein a fraction of grains in which the martensite phase and the bainite phase are mixed in a single grain of an entire fraction (area fraction) of the hard phase is 50% or more, and a carbon distribution in the grain satisfies the following Relational Expression 2, wherein the hot-rolled steel sheet has a tensile strength (TS) of 980MPa or more, and a yield ratio (YR = YS / TS) of 0.8 or less, wherein an expansion ratio of the pipe is 85% or more compared to an elongation of the hot-rolled steel sheet after pipemaking the hot-rolled steel sheet, wherein the parameters are measured according to the description. 4 < Mn/Si < 12 where, Mn and Si mean the weight content of each element, 1.2 ≤ P CB / P CC ≤ 2.0 where, PCB means a measure value of EPMA intensity of carbon at 70% point of a distance from a center of the grain in which the martensite and bainite phases are mixed in the hard phase to a boundary of the grain, and PCC means a measurement value of the EPMA intensity of carbon at a central point of the same grain, measured according to the description. <EOS>