Organic materials are essentially expected to meet emerging technological demands that realizing flexible and wearable organic field-effect transistor (OFET) devices. In this work, we first report the pentacene based OFET that fabricated on ultra-flexible 2 μm parylene C (PC) substrate. The ultra-flexible transistor was attached on silicon, glass and kapton flexible substrates and the characteristics were compared. Furthermore, the flexible OFET worked stable and obtained high mobility of 0.15 cm2V-1S-1 and current on/off ratio of 1.5×105 under bending condition. Then, the flexible nano-floating memory (NFGM) devices by using gold nanoparticles (Au NPs) and PC electrets as the charge store were realized, and the memory performances were demonstrated. In particular, the multi-level data storage were achieved from our flexible NFGM, which could be explained the deeper level trapping behavior of NPs and these energy levels of trapped sites in PC polymer electrets. The large memory window of 23 V were obtained by application of VGS pulse of ± 40 V. In further, the bending stability/mechanical stability test with stable retention property more than 105 s, and reliable cycling endurance over 500 cycles were obtained. The results highlight the utility of combing the charge store medium in flexible NFGM devices.