In this work, we presented the measurements and calculations for the optimal pump conditions and their effects on thermal lens, fracture limit and laser efficiencies of end pumped Tm-doped yttrium aluminum perovskite (Tm: YAP) laser rod pumped at 1 064 nm. The results showed that the measured overall efficiency of produced laser at -1.98 μm is enhanced from 3.9% to 6.9% when the pump spot diameter is reduced from 390 μm to 210 μm. The maximum output power and oscillation threshold are also enhanced with reduced pump spot size. The maximum thermal stress and focal length of thermally induced lens are also addressed.