Recently, thin-component and/or ferrite-Titanium welding had widely used in the product of golf head clubs. And, some small porosity was occurred during manufacturing resulting to the low strength of the golf club and the ability of surface treatment. Therefore, micro-laser welding has been used. However, seldom standards concerning the micro-laser welding were established. Therefore, the purposes of the present studies were to investigate the optimum condition of micro-laser welding on the Ti-6Al-4V alloy with the different structure. In addition, the morphology was examination by use of scanning electron microscope. Some results are described as following: 1.The morphology of the micro-laser welding on the Ti-6Al-4V alloy is essentially included, center fusion zone, re-melting ridge zone, heated affect zone, oxygen reaction zone, and some spraying tearing. 2.The higher voltage and charging numbers would induce the shrinkage within the center fusion zone. 3.Some crack nucleated from the re-melting ridge zone, and grew toward the center fusion zone. 4.In the heated affect zone, some α-case and grain growth were found. In addition, the orientation of the grain was changed. 5.When the alloy possessed lamella structure, the amount of the center fusion shrinkage, the heated affect zone and the α-case would be increase. 6.The optimum condition of micro-laser welding could be respected as a factor ,while the heat treatment different, the Q will be different. , A≒13.93；m：3350；T= K,Therefore the lamella structure might allow Q quite low.