Question

Relative density of substance depands upon what

Answer 1

relative density depends on density of substance and density of water or of that other substance which is taken as a respect of the first one

Answer 2

Relative density of a substance depends upon density of substance and density of water or any substance

also, depends on temperature.

More info:

The density of substances varies with temperature and pressure so that it is necessary to specify the temperatures and pressures at which the densities or masses were determined. It is nearly always the case that measurements are made at nominally 1 atmosphere (101.325 k Pa) but as relative density usually refers to highly incompressible aqueous solutions or other incompressible substances (such as petroleum products) variations in density caused by pressure are usually neglected at least where apparent relative density is being measured. For true relative density calculations air pressure must be considered