Graphene oxide nano-platelets were produced from helical-ribbon carbon nanofibers by oxidation with KMnO 4 /H 2 SO 4 and further exfoliation by ultrasonication. The KMnO 4 to carbon nanofiber ratio is 1:1. TEM and AFM were used to characterize the samples. TEM shows individual nanocrystals with straight edges and SAED yields a hexagonal spot pattern arrangement, attributed to graphene layers. The thickness of the nanocrystals, measured by AFM, is approximately 1.7nm, which corresponds to a single layer of hydrated graphene oxide.