In this paper, the multisignal (different emissions/colours) temperature sensing of NaYF 4 :Eu 3+ nanoparticles is investigated, which is based on fluorescence intensity ratios (FIRs) between 5 D 0 ! 7 F J (J=1-4) and 5 D 1 ! 7 F J' emissions. The 5 D 1 ! 7 F J' (J'=0-2) emissions can be clearly observed due to the low photon energy of NaYF 4 .Based on the FIRs between different 5 D 0 ! 7 F J and 5 D 1 ! 7 F J' emissions, higher absolute/relative temperature sensitivities are obtained. Compared with the FIR between whole 5 D 0 ! 7 F J and 5 D 1 ! 7 F J' emissions, the maximum value of S a was improved from 0.27 K À1 to 5.02 K À1 and that of S r was improved from 0.89%ÁK À1 to 1.27%Á K À1 . Furthermore, the FIRs between different colours of emissions were investigated for the application of wide-range multicolour temperature sensing.