We collect the scorpions, Isometrus maculates, in different instars to analyze the
photoluminescence (PL), micro‐structure of cuticles and their correlation. The photoluminescence is
excited by 405 nm solid laser in room temperature and detected by BWtek BRC 112E spectrometer. The
result shows that the intensity of photoluminescence positively correlate to instars of scorpion. The
images of micro‐structures of cuticles captured by scanning electron microscope (SEM) present the
multilayer structure in detail. The samples are prepared in small piece to ensure that the PL and SEM
data are caught from the same area. The correlation between instars and intensity of
photoluminescence is explained according to micro‐structures via the thin‐film optics theory.