We propose a method to study lattice QCD at finite T and μ. We compare it with direct results and with the Glasgow method by using nf =4 QCD at Im(μ)≠0. We locate the critical endpoint (E) of QCD on the Re(μ)-T plane. In this study we use nf =2+1 dynamical staggered quarks with semi-realistic masses on Lt = 4 lattices.
