Ash accumulation is a considerable factor for long-term Diesel Particulate Filter (DPF) performance. Ash accumulation reduces the open frontal area (OFA) and plugs the surface pores. As a result, DPF back pressures with no soot (hereinafter “initial DPF back pressure”) rise. At the same time, DPF back pressures with soot (hereinafter “sooted DPF back pressure”) fall [ 1 , 2 , 3 , 4 ]. Then sooted DPF back pressures rise after the reductions of the certain ranges [ 1 , 3 , 4 ]. It is known that DPF back pressure behaviors change variously by ash loading like this. The understanding of DPF back pressure behaviors with ash accumulation is indispensable for proper after-treatment system management. Ash accumulation progresses slowly and gradually in DPF while using of vehicles. Because of the slowness, the field surveys require a few years at least. To evaluate the effects within shorter terms, various accelerated test methods (ex. burning of lubricant oil [ 3 , 4 ], mixing of lubricant oil in fuel [ 5 , 6 ], and introduction of lubricant oil mist in intake air [ 7 , 8 ]) have been reported as alternative test methods. The test periods require a couple of months because the accelerations of those test methods were restricted by consumption rate of lubricant oil. An artificial ash accelerated accumulation (AAAA) test was attempted for drastic shortening of the test periods. This paper describes the procedures and results obtained by the attempt. The results are compared with literature and the validity of proposed test method is discussed.