Fine structures of electronic spectra of one-dimensional lattice with incommensurate potential Hn,n= 1.9*(cos(0.7n) + l/3*cos(1.4n))Hn,n-1=Hn,n+1= 1 are obtained. The precise positions of mobility edges are found by means of self-energy convergence criterion. Self-similarity in spectra and mobility edges are discussed.