To　increase　the　storage　capacity　per　unit　area,　the　traditional　strategy　is　reducing　the　storage　capacity　per　unit　area,　which　will　face　bottlenecks　such　as　the　physical　limits　of　device　size.　People　are　turning　their　attention　to　multi-level　memory　devices　that　can　achieve　high-density　storage　on　a　single　device.　In　this　paper,　a　multi-level　memory　device　with　optical　write　operation　is　fabricated　by　using　the　persistent　photoconductivity　(PPC)　effect　in　organic　thin　film　transistors,　which　effectively　avoids　the　contact　destructiveness　and　large　work　consumption　of　the　device　by　the　electrical　write　operation.　The　device　storage　state　under　different　power　(60,　100,　150　μW/cm2)　and　different　duration　(50-1　000　ms)　700　nm　optical　write　pulse　was　studied.　It　exhibited　extremely　low　operating　power　as　low　as　0.189　nJ　under　the　optical　pulse　with　power　of　60　μW/cm2　and　duration　of　100　ms.　When　16　consecutive　optical　write　pulses　were　applied,　the　device　showed　16　distinct　effective　storage　state,　it　meant　that　multi-level　optical　write　storage　function　with　a　storage　capacity　of　4　bits　was　realized　in　this　device.　©　2020,　Science　Press.　All　right　reserved.