Hi , richard, thanks for your reply.
Under /usr/local/cuda-8.0/lib64/cuDNNv6/ there are:

and under /usr/local/cuda-8.0/include/cudnnv6/ there is cudnn.h.
export CUDNN_INCLUDE_DIR=/usr/local/cuda-8.0/include/cudnnv6/
exprot CUDNN_LIB_DIR=/usr/local/cuda-8.0/lib64/cuDNNv6/
Setting these two environment path dose not work. And setting LD_LIBRARY_PATH and C_INCLUDE_PATH & CPLUS_INCLUDE_PATH also dose not work.
It seems that pytorch can only find cudnn in /usr/local/cuda-8.0/lib64/ and /usr/local/cuda-8.0/include.