We obtained a solution structural model of myoglobin (Mb) formed upon the CO photolysis of MbCO by analyzing time-resolved X-ray Solution scattering data. An experiment-restrained rigid-body molecular dynamics simulation was used to find the best model whose theoretical difference scattering curve gives it satisfactory agreement with the experimental data at the time delay of 10 nus. The obtained Solution model shows structural changes similar to crystallographic models for MbCO -> Mb but also displays a noticeable difference in that the N-terminus and F helix show larger structural changes.