Abstract: Four single chemicals and six formulations were tested in laboratory. The results showed that (1) in controlling blue stain fungus (Bot-ryodiplodia theobromae Pat), TWP is the best one in the test and its toxic limit concentration is at 1%, (2) in controlling mixed moulds (Trichoderma lignorum, Penicillum citrinum and Aspergillus niger), TWP is as good as NaPCP or MECT (or ANTIBLU 3738 or TCMTB + MBT). To prevent blue stain and moulds on rubber wood, the chemical treatment and testing method were also discussed.