My son aged 7 years is having micro penis below one inch. His weight is 50 kgs?

Hi

The only think you can do is to take him to a doctor so he can have testosterone treatment.. If you leave it for later it will be too late and he will have a small penis for his entire life, might even hate you for not taking to a doctor. Just google testosterone treatment micropenis although you will mostly get pubmed results like this one:
http://www.ncbi.nlm.nih.gov/pubmed/6497555

In short, just take your son to a doctor. He will have a couple of injections, some side effects (including a bigger penis) and he will thank you when he gets older

What does the pediatrician think? He may yet grow when he comes into puberty. Penis size has nothing to do with whether or not he will be able to father children. Often penis size is genetic. If the mothers family males have small penises or the father of the child has a small penis, so will the child and vice versa for large penises. There is nothing that will specifically make a penis grow. If your child doesnt come into puberty when he becomes a teenager then they may be able to do growth hormone. Dont worry about it at this point and try not to make a big deal of it to the child so that he doesnt develop a psychological problem about having a small penis. He is too young for you to worry about it at this point. He is only 7.