[Objectives]  The larvae of Depressaria falkovitshi Lvovsky (Lepidoptera: Elachistidae: Depressariinae) are an important pest of Bupleurum falcatum L.; damaging the leaves, stem tips and inflorescences of this plant. Classification of D. falkovitshi larval instars could be important for developing control measures for this pest. [Methods]  In this study, the head capsule width and body length of larvae were measured ,then the larval instars were identified on the basis of frequency histograms and Dyar’s law. The rationality of instars was verified by Crosby’s growth rule and linear regression. [Results]  The results suggest that the larval stage of D. falkovitshi is comprised of 5 instars with an average head capsule width (mm) of; 0.163±0.006, 0.262±0.012, 0.437±0.025, 0.690±0.038 and 1.116±0.051, respectively. The linear relationship between head capsule width (y) and instar (x) was: y=0.101e^0.4815x, R² = 0.9998. [Conclusion]  Head capsule width can be used  to reliably identify larval instars but body length is too variable.