There are many factors influencing the growth and secondary metabolites of callus and saffron callus. In this paper, the effects of culture conditions, including culture temperatures, light levels, the carbon source and its concentration, and the preserve of regulators (mainly hormones), are studied for callus cultures. All the experiments used Murashige and Skoog (MS) solid medium as the basic medium with 10 g/L agar, pH 5.75.8. Saffron callus was cultured at 20℃ in the dark, with a sucrose concentration of 45 g/L (or starchy hydrolysate concentration of 40 g/L), but 30 g/L sucrose was best for the synthesis of crocin (for starchy hydrolysate the concentration can range from 20 to 40 g/L). To promote callus growth, the best auxin was α-naphthaleneacetic acid (NAA) and the optimum ratio of NAA (mg/L) to benzylaminopurine (BA) (mg/L) was and uniconazole (S-07) (1.25 mg/L) increased the crocin content remarkably as analyzed by high performance liquid chromatography (HPLC). NAA (2 mg/L) promoted the growth of saffron callus but had no benefit and may inhibit crocin synthesis while S-07 (1.25 mg/L) had the opposite effect. GA3 promoted both growth and synthesis.