A non-spherical resin particle giving a projection image viewing from at least one direction of approximately regular hexagonal shape in which each of the sides is convex to out side, wherein the particle satisfy the following formula when circumference length and the major diameter of the projection image of the non-spherical particle are each a and b, respectively, (3/.pi.).ltoreq.{a/(b.times..pi.)}.ltoreq.C.995, and the method for producing such the particle is characterized in that the method includes a step for forming the particle having the specific approximate hexagonal outline in a projection image viewing at least one direction by removing a swelling liquid from a swollen particle which is prepared by swelling a true-spherical particle by the swelling liquid containing a swelling agent and positioned on a substrate in a state of that the center portions of each of the adjacent three swollen particles are each positioned at each vertex of a regular triangle on a plane. To provide a non-spherical resin particle having a specific shape by which sufficient strength and positional precision can be obtained, and a production method thereof.