The new index of the s cientists' popularity es timation is represented in the paper. The index is calculated on the basis of Wikipedia encyclopedia analysis (Wikipedia Index - WI). Unlike the conventional existed citation indices, the suggested mark allows to evaluate not only the popularity of the author, as it can be done by means of calculating the general citation number or by the Hirsch index, which is often us ed to meas ure the author.s res earch rate. The index gives an opportunity to es timate the author.s popularity, his /her influence within the sought-after area "knowledge area" in the Internet - in the Wikipedia.