Disclosed is a method for preparing a rubber latex which includes adding a basic solution to an initial reaction hydrophilic monomer and a small amount of fat-soluble monomer when a polymerization conversion ratio is 90% or more to form particles having a small diameter and superior stability, ionizing an end of the particles to secure stability of the particles and growing the formed particles, and thereby obtains a stable latex with a large particle diameter using a minimal amount of emulsifying agent and minimizes gas generation and heat discoloration derived from the emulsifying agent.