To purify transforming growth factor type beta(TGF-$eta$) in canine platelets, Sephadex G-75 gel filtration and semipreparative HPLC were carried out. The column of $2.0 { imes}120cm$ was used for gel filtration and one inch semipreparative column filled with SP-Toyopeal for HPLC. Electrophoresis and bioassay using African green monkey kidney cell were used for identification of TGF-$eta$ Crude TGF-$eta$ of 2.75mg was extracted from 5.2g of the platelets by the treatment of acid/ethanol. In gel filtration of crude TGF-$eta$, 4 peaks were observed at the detection of spectrophotometer at 280nm. Electrophoresis and bioassay identified the 3rd peak TGF-$eta$. Linear gradient elution from 0 to 3M NaCl in sornipreparative HPLC showed TGF-$eta$ at 1.5M NaCl. Gel filtration was less expensive and useful method for the purification of TGF-$eta$.