This work presents an experimental study of soot and polycyclic aromatic hydrocarbons (PAH) distribution in axisymmetric ethylene-air non-premixe laminar flames using spectroscopic diagnostic in a co-flow target burner. For this purpose, are applied laser-induced fluorescence and laser-induced incandescence techniques with UV excitation. Spectral detection bands centered at 340, 400, 450, 500, 550 nm are employed to characterize PAH, using the infrared fluorescence spectra displacement phenomenon with the molecular mass increase. The incandescence is captured at 400 nm and the laser extinction technique is used to calibrate the signal, and, thus to obtain the soot volume fraction at the reaction zone. The soot spontaneous emitted radiation is used to measure the temperature by the two-color pyrometry technique. The comparison between results with prompt (0 ns) and delayed (50 ns) detection, with respect to the laser pulse, allows to discriminate the regions between soot precursors (PAH) and soot. The results show that, in the colder region, near the fuel inlet, PAH exist only. Following this region, in an intermediate warmer zone, both soot and PAH appear to coexist until the point of maximum integral soot volumetric fraction. A vertical displacement of the fluorescence distribution with increasing detection wavelength is observed, which is consistent with PAH size growth and with its progressive transformation into soot. PAH and soot distribution are investigated as a function of the fuel flow rate. The soot volumetric fraction exhibits a classical distribution, whose value increases with the fuel flow rate, whereas the measured temperature decreases, exhibiting a singular behavior in the region where the soot is formed.