It is a hot topic to use the online algorithm and competitive analysis to study the online leasing problem． Based on the study of online leasing of general equipment，the online leasing of depreciable equipment is discussed． Since randomized algorithms can boost up performance，the randomized strategies for online leasing of depreciable equipment with oblivious adversary is proposed both with and without consideration of interest rate，respectively，and the maximum of its optimal competitive ratio is also obtained respectively． The conclusion shows that the introduction of depreciation factor made competitive performance improved． The introduction also makes the model more practical for large-scale investment in equipment problem，and provides investor better theoretical basis for decision making． In addition，consideration of interest rates makes the competitive ratio decrease a little，that is，investor will take more prudent investment strategy when interest rate is taken into consideration