The nonlinear analysis of the temperaturetime series at nucleation site in a typical nucleate boiling heat transfer experiment in different heat fluxes is presented.The threedimensional attractors of the temperaturetime series are reconstructed.Then,from the threedimensional attractors,the correlation dimensions,which reflect the complex character of the attractors,are calculated and the computation of the maximum Lyapunov exponents of the temperaturetime series is carried out in different heat fluxes.The calculation result of the maximum Lyapunov exponent,a parameter quantitatively estimating whether a physical process has the character of chaos,shows that the temperaturetime series at the nucleation site does have chaos characters.