Present status of the measurement of R value and form factors of e+e− → π+π−π+π− and at BES

The present status of the measurement of R value with the new data taken at four energy points, 2.2, 2.6, 3.07 and 3.65 GeV, are described, and the systematic errors are estimated. The preliminary results for the cross sections and the form factors about the e+e−→π+π−π+π− and between 2.0 - 3.65 GeV are presented.