In order to evaluation of the spraying time and cobult nanoparticle fertilizer using chemical and green chemistry methods on morphophysiological indices of cowpea, this research was conducted in a factorial experiment in a the experiment was conducted Randomized Complete Block Design (RCBD) with three replications in Agricultural Research Institute University of Zabol in 2017.The experimental included 4 levels of treatments: (Cobult nanoparticles of plant origin, chemical origin, plant and chemical composition and control), as the first factor and time of spraying in 2 levels (Step 4and Step 6 leaf the second factor). The plant density of cowpea was 20 plants/m2 and irrigation was performed twice a week. The results of analysis of variance showed that the time of foliar application and application of nano particles of chemical and plant origin had a significant effect on all studied traits. Based on the results of average comparison, the highest amount of chlorophyll a (13.25 μg/g leaf), chlorophyll b (7.50 μg/g leaf), carotenoids (3.63 μg/g leaf), as well as plant height (34.84 %), number of pods per plant (28.26%), biological yield (45.64%), economic yield (59.10) compared to control treatment, iron (0.26 ppm) and leaf protein ( (46/14 ppm) was obtained from the six-leaf stage and from the combined application of cobalt nanoparticles with chemical and plant origin. In terms of all the measured traits, it seems that simultaneous application of cobalt nanoparticles chemically and vegetative, through improving the photosynthetic system, increasing leaf duration and photosynthesis, will lead to increased biological and economic yield.