中文摘要：

针对BLAST算法在查找命中的过程中需要遍历数据库造成计算资源消耗的问题，提出了基于位图索引和B＋树的数据存储方式以加快数据的检索。改进算法利用位图索引的原理建立数据库的单词．位向量表，并对这个表使用B＋树再次进行索引，最终达到加快BLAST程序的运算速度。对于DNA序列这个方法能够使BLAST查找命中耗费的时间得到极大的减少。

英文摘要：

It concentrates on the time consuming procedure that goes through the database in the first step of BLAST. In order to speed up the program, it introduces a new approach which using bit map index and B＋ tree. The developed method builds up a word-bit_vector table according to the database, and reorganizes it with B＋ tree. It proves theoretically that it decreases the word searching time of BLAST substantially.