Here my code:
  2 import sys
  3 import ctypes
  4      
  5      
  6 def hi():
  7     class timespec(ctypes.Structure):
  8     ┆   """Time specification, as described in clock_gettime(3)."""
  9     ┆   _fields_ = (('tv_sec', ctypes.c_long),
 10     ┆   ┆   ┆   ┆   ('tv_nsec', ctypes.c_long))
 11      
 12      
 13     ts = timespec()
 14     po = ctypes.pointer(ts)
 15      
 16      
 17 def main():
 18     while True:
 19     ┆   test = hi()
 20      
 21 if __name__ == "__main__":
 22     sys  2 import sys
  3 import ctypes
  4      
  5      
  6 def hi():
  7     class timespec(ctypes.Structure):
  8     ┆   """Time specification, as described in clock_gettime(3)."""
  9     ┆   _fields_ = (('tv_sec', ctypes.c_long),
 10     ┆   ┆   ┆   ┆   ('tv_nsec', ctypes.c_long))
 11      
 12      
 13     ts = timespec()
 14     po = ctypes.pointer(ts)
 15      
 16      
 17 def main():
 18     while True:
 19     ┆   test = hi()
 20      
 21 if __name__ == "__main__":
 22     sys.exit(main())

run this code, i find that the program occupy more and more VmRss
my python is 2.7.11, in python3 i also find this problem. 
   Is this normal？I am a newbie with python, not very familiar with some 
python's internal principle. 
   Tanks.

The tracker is for patching CPython.  Please consider closing this and asking your question on python-list.  When you post code, do so only once, and without line numbers, so it can be copied and run as is.  Do include data on the ref leaks.

I agree with Terry. Your code calls hi() in an infinite loop (why timespec is defined in hi()?), we don't know how clock_gettime(3) is implemented etc. (it should cleanup its own memory if it calls malloc()) etc. Please use python-list or StackOverflow for usage questions.

See also issue 12998.