An ultrasonic diagnostic apparatus comprising: a setting unit which sets, on an ultrasonic image of a heart, a plurality of observation points (A to F, H, I) on conduction pathways of the heart for an electric signal which causes contraction of a cardiac muscle; a tracking unit which tracks each of the observation points (A to F, H, I) to determine a two-dimensional displacement vector of each of the observation points; and a waveform generating unit which generates a plurality of displacement waveforms (L1, L2, L3, L4) based on the plurality of two-dimensional displacement vectors determined for the plurality of observation points (A to F, H, I); characterized in that an analyzing unit is provided which analyzes the plurality of displacement waveforms (L1, L2, L3, L4) on a common time axis to calculate a time difference of motion (M1, M2, M3) for the plurality of observation points (A to F, H, I), the plurality of observation points (A to F, H, I) include a proximal observation point which is set on an upstream side on the conduction pathway and a distal observation point which is set on a downstream side on the conduction pathway, the plurality of displacement waveforms (L1, L2; L3, L4) include a proximal displacement waveform generated based on the two-dimensional displacement vector of the proximal observation point and a distal displacement waveform generated based on the two-dimensional displacement vector of the distal observation point, and the analyzing unit calculates, as the time difference of motion (M1, M2, M3), a relative delay of the distal displacement waveform with respect to the proximal displacement waveform. a setting unit which sets, on an ultrasonic image of a heart, a plurality of observation points (A to F, H, I) on conduction pathways of the heart for an electric signal which causes contraction of a cardiac muscle; a tracking unit which tracks each of the observation points (A to F, H, I) to determine a two-dimensional displacement vector of each of the observation points; and a waveform generating unit which generates a plurality of displacement waveforms (L1, L2, L3, L4) based on the plurality of two-dimensional displacement vectors determined for the plurality of observation points (A to F, H, I); characterized in that an analyzing unit is provided which analyzes the plurality of displacement waveforms (L1, L2, L3, L4) on a common time axis to calculate a time difference of motion (M1, M2, M3) for the plurality of observation points (A to F, H, I), the plurality of observation points (A to F, H, I) include a proximal observation point which is set on an upstream side on the conduction pathway and a distal observation point which is set on a downstream side on the conduction pathway, the plurality of displacement waveforms (L1, L2; L3, L4) include a proximal displacement waveform generated based on the two-dimensional displacement vector of the proximal observation point and a distal displacement waveform generated based on the two-dimensional displacement vector of the distal observation point, and the analyzing unit calculates, as the time difference of motion (M1, M2, M3), a relative delay of the distal displacement waveform with respect to the proximal displacement waveform.