Reducing height and increasing tiller number of rice is Paclobutrazol, which has been used by farmers for a long time and high contents. The main aims of this study were evaluated: (i) effects of paclobutrazole on the growth, yield composition and yield of rice OM18, (ii) PBZ accumulation of crop soil and its accumulation on stems and grains. The field experiment was carriout in randomized complete block design (RCBD) with four plots (R1: 70 N - 60 P - 30 K kg/ha, R2: 3.0 kg PBZ/ ha, R3: 3.5 kg PBZ /ha, R4: 4.0 kg PBZ /ha) and four replications. The research results observed that soil pH and plant height of PBZ amendment treatments (R2, R3 and R4) reduced significantly comparison with control treatment (R1). Number of available tillers at 42 DAS in three treated treatments of PBZ were higher than those of control treatment. However, there were insignificant differences and remarkable decrease of available tillers at 72 DAS. The yield composition and yield of rice OM18 were not remarkably various among treated and untreated treatments. Especially, PBZ store of soil, stems and grains was higher than the control treatment from 76.2, 98.6 and 100%, respectively. From this study, it may be suggested for local farmers to stop using PBZ, which can improve to pollute the crop soil environment and enhance agricultural quality.