Wellhead & X'mas assembly, the key equipment in oil/gas produation, consist of casing head, tubing head and X'mas tree, which are applicable for connetion of casing string and tubing, as well as sealing the annular space between casing and tubing and controolling the pressure of the production wellhead and adjusting the flow rate of oil/gas wellhead. It's also applicable for special operation such as acid fracture, injection and test etc.