Objective: To study the effects of different concentrations of antisense oligodeoxynucleotides (ASODN) on human pancreatic cancer cell line PaTu8988s. Method: Human pancreatic cancer cell line PaTu8988s in exponential growth stage was used to study the effect of different drug concentrations on the cell line in the presence of different concentrations (0 μg/ml, 5 μg/ml, 25 μg/ml, 50 μg/ml, 10 μg/m, 200 μg/ml) of ASODN and sense oligodeoxynucleotides (SODN). Cell counts and 3-[4,5-dimethylthiazolzyl]-2,5-diphenyl tetrazolium bromide (MTT) assays were carried out. Results: The inhibitory rate on the cell line PaTu8988s was 98.73%,95.76%,69.49%,33.05% and 0 for ASODM concentrations of 200 μg/ml,100 μg/ml,50 μg/ml,25 μg/ml and 5 μg/ml at 48 hours. Conclusions: K-ras complementary ASODN can inhibit the growth of human pancreatic cancer cell line PaTu8988s by 30.05% to 98.73%. This is likely to contribute to the specificity of the K-ras mRNA complementary capped ASODN sequential codon. Non-specific effect and side effect of ASOND were observed for instance, the greater the concentration is, the earlier the peak of inhibitory rate is reached. In concentration of 25 μg/ml to 100 μg/ml ASODN showed a dose-effect correlation