Alternative splicing is the RNA splicing variation mechanism. The exon isoforms lead to numerous different expressions through the alternative splicing. It's imperative to find the carcinogenic gene from the massive quantity of genes and understand the expressed isoforms. In this paper, the statistical procedures are applied on the colon cancer sample data of Affymetrix GeneChip Human Exon 1.0 ST Array and the dataset is used as the example of finding isoforms. First, the Wilcoxon sign rank test was applied to choose the suspect carcinogenic genes. About 54,854 suspect genes are selected from original 312,368 genes at 5% significant level. Second, one sample t-test and the factor analysis are used to estimate the tumor and normal isoforms for each suspect carcinogenic gene, respectively. Furthermore, the confirmations are made by comparing the estimated results with Alternative Splicing Database. Finally, the results may be provided to the biologist to make biological confirmations and discover the new isoforms.