Quality and quantity of food largely influence the growth and survival of small abalone Haliotis diversicolor post larvae. How to manage the diatom films is a key issue for successful and stable rearing small abalone post larvae. Traditionally using naturally occurring diatoms could somewhat control the quantity, but hardly the quality. Several diatom species were isolated, stock cultures were hold and culture technique was established. Application the cultured diatom, three batches of small abalone juveniles, reared during the end of 2005, matured and spawned in 2007. The F2 generation again fed the cultured diatom as its food. At age of 55 days post hatching, averagely 200 individuals with 5-10 mm shell length on the plastic plates was found, the settlement rate reached 14 % calculated from the swimming larvae stage. At 134 days post hatching shell length is 0.8-2.5 cm. The technique using the cultured diatoms to successfully rear the small abalone juveniles will be used for the selecting and breeding the quality spawners for steadily production of juveniles.