Select at least one Y column of values (or a range from at least one column). If there is an associated X column, X column supplies X values; otherwise, sampling interval of the Y column or row number is used.
Select required data.
Select Plot > Bar, Pie, Area: Stacked Area from the main menu.
Click the Stacked Area button on the 2D Graphs toolbar.
STACKAREA.OTP (installed in the Origin program folder).
When one Y column of values (or a range from one column) is selected, the area between the data plot and the "From" Y axis value is filled by default. When multiple Y columns (or ranges) are selected, each successive column of values is displayed as an area graph that is stacked on the previous area graph. The upper bounds of the first area graph is treated as the baseline of the next area graph. To plot each of the data plots so that the area between the data plot and the "From" Y axis value is filled, select Graph: Offset Grouped Data in Layer: None.
To create a 100% stacked area graph, double click on the graph to open the Plot Details dialog, check the Normalize to Percent for Cumulative/Incremental checkbox in the Stack Tab at the layer level.