Let f:X→X be a selfmap of a compact connected polyhedron, using Nielsen fixed point theory, we give a better lower bound for topological entropy h(f) of f . In addition, if f:Tm→Tm is a selfmap of m-trous, some conditions under which log N∞(f) is a best lower bound for {h(g)|g≈f:Tm→Tm} is obtained where N∞(f ) is asymptotic Nielsen number of f, and hence we get the answer for a question put by Professor Boju Jiang. |