Hydroxyapatite(HA) coatings were deposited onto titanium alloy substates using the microplasma spray(MPS) technique.The fractional-factorial experiment design method was employed to study the rellationships between MPS parameters(amperage,plasma gas flow rate,spray distance and powder rate) and characteristics of HA-coatings(microstructure,morphology,content of crystalline and amorphous phases,texture).Influence of coating thickness and presence of underlayer(from titan or titania) was evaluated also. The results show some peculiarities of HA-coating formation in conditions of microplasma spraying process.