diff --git a/src/processor/dataSample.js b/src/processor/dataSample.js
index a1cce6ecd8..1dca57a980 100644
--- a/src/processor/dataSample.js
+++ b/src/processor/dataSample.js
@@ -73,8 +73,9 @@ export default function (seriesType) {
                         sampler = sampling;
                     }
                     if (sampler) {
+                        // Only support sample the first dim mapped from value axis.
                         seriesModel.setData(data.downSample(
-                            valueAxis.dim, 1 / rate, sampler, indexSampler
+                            data.mapDimension(valueAxis.dim), 1 / rate, sampler, indexSampler
                         ));
                     }
                 }