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In a recent experimental study of indentation creep, the strain rate sensitivity (SRS) and activation volume <inline-formula><math display="inline"><semantics><mrow><msup><mi>v</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula> have been noticed to be dependent on the indentation depth or loading force for face-centered cubic materials. Although several possible interpretations have been proposed, the fundamental mechanism is still not well addressed. In this work, a scaling law is proposed for the indentation depth or loading force-dependent SRS. Moreover, <inline-formula><math display="inline"><semantics><mrow><msup><mi>v</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula> is indicated to scale with hardness <inline-formula><math display="inline"><semantics><mi>H</mi></semantics></math></inline-formula> by the relation <inline-formula><math display="inline"><semantics><mrow><mo>∂</mo><mi>ln</mi><mo stretchy="false">(</mo><msup><mi>v</mi><mo>*</mo></msup><mo>/</mo><msup><mi>b</mi><mn>3</mn></msup><mo stretchy="false">)</mo><mo>/</mo><mo>∂</mo><mi>ln</mi><mi>H</mi><mo>=</mo><mo>−</mo><mn>2</mn></mrow></semantics></math></inline-formula> with the Burgers vector <inline-formula><math display="inline"><semantics><mi>b</mi></semantics></math></inline-formula>. We show that this size effect of SRS and activation volume can mainly be ascribed to the evolution of geometrically necessary dislocations during the creep process. By comparing the theoretical results with different sets of reported experimental data, the proposed law is verified and a good agreement is achieved.