Dear Rishikesh Bhaskar, Check. May be be the following link may help you.

http://www.mathworks.in/matlabcentral/fileexchange/32374-matlab-support-package-for-arduino-aka-arduinoio-package

Thank you sir for replying but i have already used those packages of MATLAB.....but those packages are won't work.......!!

Arduino port tends to change into different COM port numbers when you also have other peripherals attached via USB to your system. Did you check the current port number the Arduino is assigned into your system? Also makes sure the baud rate is properly set.

hi

since all of problems with arduino related to hardware, adjustments ,and  software

firsly it s better to recognize the origin of the problem,

to be sure that the hardware and/or com port is working correctly,it s better to install arduino software,(which is free) and after some parameter adjustment  try to connect  to  atmaga8,

regards

alireza goudarzvand