...science? I've bacholers degree in mechanical engineering.But I've work experience of 4 years in Software field.I want to do MS. Is general test enough for me or I need to take subject test for Computer science?Please answer this. I need to make quick decision now or I would've to wait till next year.

That really depends on the university. Some of the less competitive programs make it optional and they might even work with you so that you can fulfill some of the undergraduate deficiency courses. For the more competitive programs, since your degree was in something other than CS, it would impress the admissions committee if you can score high on the subject GRE to demonstrate that you are ready for graduate courses. So really, you should check the websites of the universities you are interested. However, I don't know if you have taken a look at the CS GRE but it tests a wide range of topics, not just software and programming, such as architecture and networking.