Micro-organisms, tissues, cells, organelles, enzymes, peptides and DNA are used to identify the target substance called as a specific or non-specific biosensor. A bioassay is a biological testing procedure for estimating the concentration of a substance in a formulated product or bulk material.  Due to the importance of flavonoids as antioxidants and expensive and time-consuming methods, bioassay of flavonoids via biosensor is growing. Plant bionanosensor is a new approach and a certain type of biosensor that converts the concentration of flavonoids into visible rotation and flavonoids are detected by different rotations of concentration. The rotations of Ccrataegus oxyacantha (Hawthorn) extract (flavonoids) with plant bionanosensor were analyzed in a completely randomized design with three replications by sas9.1 software. The different levels of flavonoid rotation are significant with a probability of 99%. So far, no report was made on plant biosensor.