In the present study, as a part of our program, we have focus on a new approach to search for the new NR latex preservatives. The preservatives used in the study consist of zinc sulfate, silver nitrate, silver protein, lithium hydroxide, sodium hydroxide, potassium hydroxide, ethanolamine, methyl1-4-hydroxybenzoate and propyl1-4-hydroxybenzoate. preservative activities for treated field natural rubber latex were investigated based on measurement of volatile fatty acid (VFA) number of the treated latex and microorganisms concentration.