the two map (Heat map and bubble chart) mixed

Hi Yutaka,

Thanks for your question.
Sure you can place multiple RenderableSeries on the single SciChartSurface. Please take a look at our “Series Binding” example for more info:
https://www.scichart.com/example/wpf-chart-example-series-binding/

And “Manipulate Series MVVM” example:
https://www.scichart.com/example/wpf-chart-example-manipulate-series-mvvm/

You can also add HeatMapRenderableSeriesViewModel to the ObservableCollection. Please take a look at our documentation regarding MVVM API:
https://www.scichart.com/documentation/v5.x/webframe.html#MVVM%20DataSeries%20RenderableSeries%20API.html

Hope this helps.