The Fragmentation Functions is one of the non-perturbative components of the QCD factorization theorem. They represents the probability of a parton carrying a fraction z of momentum to transform into a particular kind of hadron. In this work, we study the jet fragmentation functions in the collisions between electrons and positrons. The jets where identified with Fastjet for different p_{Tchjet} intervals. The intervals and the final jets were reconstructed by means of the event shape separation using the spherocity variable and the study is performed under Pythia Monte Carlo event generator framework.