Disclosing solution is a material that is often used to see the presence of plaque, made from the basic ingredient of erythrosine that can cause allergies. Disclosing Agents derived from natural materials are still very minimal. The utilization of natural materials will increase economic value and have a high level of safety. The purpose of the study was to give an overview on 1). stability test of secang wood extract in animals and microbial contamination test, 2). clinical on secang wood extract in human subjects as a disclosing agent ingredient. The design of this study is an experimental study by conducting a white rat stability test, microbial contamination test and clinical trials on human subjects on secang wood extract gel as a disclosing agent. Tools and materials used, the tools are oven, grinder, mechanical sieve, maceration vessel, hydraulic press, rotary evaporator, water bath, sterile test tube, glassware, aeration, glass container, UV-Vis spectrophotometer and the materials used, namely secang wood, Brazilian standard, ethanol pro analysis, methanol pro analysis, hexane pro analysis, ethyl acetate pro analysis, Aqua Sterile, Whatmann paper, FeCl3, HCl. Research results, stability tests include homogeneity, viscosity, adhesion. The dispersion and pH are in accordance with the range in the literature. Followed by a statistical normality test that shows normal distributed data, then a homogeneity test of the data obtained is carried out. The viscosity, adhesion, dispersion and pH tests showed no significant differences between the 0th month, 1st month, 2nd month, and 3rd month data. In conclusion, the stability test includes organoleptic, viscosity, adhesion, dispersion and Ph showed that the gel preparation of secang wood extract is physically stable, the SPSS test has no significant differences, there is no bacterial contamination in the secang wood extract gel preparation within 3 months. Clinical trials conducted on respondents showed plaque detection and were in accordance with the contrast color of the disclosing agent.