Abstract: Provided herein is a drug delivery (DD) system for ratiometric luminescence determination of drug release degree in drug delivery monitoring, which includes a drug, a switchable reporter and non-switchable reporter providing two distinguishable signals for detection; or a single switchable reporter providing two distinguishable signals for detection, and a cleavable linker connecting a drug to a switchable reporter, as well as a method for ratiometric luminescence determination of drug release in a target (in vivo or in vitro), which is effected by administering the DD system provided herein that is capable of releasing a drug from the DD system, measuring two luminescent signals provided by the switchable reporter and the non-switchable reporter, or the single switchable reporter, determining the ratio between these two luminescence signals, and determining the drug release degree through the ratio between the two luminescence signals.