Abstract: To investigate the relations between salidroside content and particle size as well as growth conditions, also the possible mechanism of Rhodiola crenulata, callus obtained from leaves of R. crenulata was used for raising particle suspension cultures, which were then filtered by cell sieves with 60, 80, 100 or 120 mesh respectively, so that cell suspension cultures were established. The salidroside content in particle suspension cultures (the average diameter was about 2.5 cm) and cell suspension cultures (filtered by 80 mesh cell sieve) were detected, both of the particle and cell culture solutions in the same culture conditions were also detected. After being filtered by 80 mesh cell sieve and then cultured for a period of time, the culture filtrate had been shown to produce vast rapid proliferated cell suspension cultures with uniform size. Cell suspension cultures had 0.606 mg/g of salidroside, which was about 2.2 times of that of particle suspension cultures (0.27 mg/g). However, neither of the solution of particle suspension cultures nor cell suspension cultures was found to have salidroside. It is concluded that salidroside content in suspension cultures has certain relations with particle size and growth condition of different cell aggregation. Since small cells contact fully with oxygen and nutrient of medium, they can produce high content of salidroside.