An analysis is made of pulsating laminar flow in a sinusoidally curved pipe. When there exists no steady flow, the axial velocity is larger in the inner part than in the outer portion of the pipe section. Steady flow makes the adaptation of secondary flow to the change in curvature of the pipe axis delay. When the value of the parameter k=√(ω*/ν*)r₀* is small, the degree of delay is similar to that for steady flow and is almost independent of time; but it becomes very different from the steady case and varies with time as the value of k increases.