The absorption and upconversion fluorescence spectra of Er3+ ions in Er3+ doped transparent lead lanthanum zirconate titanate(PLZT)ceramic were measured at room temperature. The radiative transition probabilities of the Er3+ ions were calculated using the absorption spectrum of Er3+ doped PLZT. Strong upconversion emission was observed in the upconversion luminescence of Er3+ doped PLZT. The green emission intensities at 540nm and 564nm were stronger than the red emission intensity at 678nm. The upconversion rate equations describing the dynamic process of the system have been deduced. The upconversion coefficients were estimated by numerically solving the rate equations and fitting the simulated curves to the measured data. The coefficients C22and C33 obtained are 091×10-18cm3/s and 1823×10-18cm3/s, respectively. The results show that evident upconvesion phenomenon can be observed in Er3+: PLZT transparent ceramics, which is consistent with our observation.