I have a dry cough for two month. It gets better for 10 days when I cough very little like twice or thrice a day and then starts again. Is it chronic?

Yes... Any cough lasting for 3 weeks or more is considered chronic. Etiologies include bronchospasm from any cause, post-nasal drip, gerd or a combination of factors. Treatments for each of these is entirely different so see your doctor so this cough can be diagnosed and treated.