Rapid sampling technique employing Spark Plasma Sintering (SPS) was implemented to produce multilayered specimens with gradual variation in the chemical composition of the TiZrAlNbMo system. Multilayered gradient specimens were sintered using elemental powder mixtures to study the effect of Nb and Mo on the phase stability of the TiZrAlNbMo based high entropy alloys (HEA). Gradient 6-layered samples with a general composition of 25Ti-30Zr-15Al-xNb-yMo and 35Ti-30Zr-10Al- xNb-yMo were sintered, varying the Nb-Mo content with steps of 5 at.% in each layer. After thermal homogenization (1400°C) and quenching  from 1200°C, the microstructural characterization was conducted by means of scanning electron microscopy, including EDS and by X-ray diffraction. It was revealed that Mo favours the formation of secondary phases, while Nb serves as a better bcc-phase stabilizer in this HEA system. The increase of Nb over Mo refined the particle size of secondary phases until reaching a threshold value to fully stabilize a single-phase solid solution. Manufacturing and characterization of gradient samples allows an efficient analysis of the effect of individual elements on microstructure and phase content in HEA, and consequently allows rapid alloy optimization.