Electromagnetic form factors provide fundamental information to reveal the internal structure and dynamincs of nucleons. Using the energy scan data collected by BESIII experiment on BEPCII collider, the Born cross section of e+e−→pp¯ and e+e−→nn¯, and the proton and neutron electromagnetic form factors are measured at center-of-mass energies between 2.0 and 3.08 GeV, through the e+e− direct annihilation process. Through the initial-state-radiation process, the proton electromagnetic form factors are also measured from the pp¯ threshold to 3.0 GeV with the large data sets collected at center-of-mass energy between 3.773 and 4.6 GeV, while the Born cross section of e+e−→pp¯ is measured up to 3.8 GeV.