UCA1 was highly expressed in gastric cancer tissues and cells, and its high expression level had a positive correlation with some malignant pathological characteristics of gastric cancer, such as higher grade and poor differentiation. Moreover, UCA1 was an independent prognostic biomarker of disease-free survival for gastric cancer patients. Silence of UCA1 could significantly inhibit the cell proliferation of gastric cancer BGC-823 and SGC7901 cells. The chemotherapy resistance to adriamycin of SGC7901/ADR cells was depressed by UCA1 silence, and IC50 for adriamycin presented a conspicuous depression. UCA1 silence advanced apoptosis induced by adriamycin in SGC7901/ADR cells, up-regulated cleaved PARP protein expression and depressed the expression of anti-apoptosis protein Bcl-2.