Optimized LaxCa0.89-xSr0.11MnO3 (x = 0.65, 0.68, 0.71 and 0.74) films were fabricated using spin-coating method. According to double exchange (DE) mechanism and Jahn-Teller effect, the enhancement of peak temperature coefficient of resistivity (TCR) was attributed to low residual resistivity and weak various electron scatterings, including electron–electron, electron–phonon and electron-magnon. Also, peak TCR temperature is not only influenced mainly by the DE mechanism, but also by the Mott transition. Moreover, optimized sintering improved film crystallinity, increasing peak TCR value. The resulting La0.71Ca0.18Sr0.11MnO3 film displayed a peak TCR of 10.74 %/K at 294.11 K. Appropriate chemical composition and sintering promoted the enhancement of electrical transport properties.