Plz remove

plz delete

Did you load your sketch? You may be running a sketch written by a previous student in your class. We know it's a class because there's a wave of questions on this particular hardware configuration.

yes I uploaded it and verified it.

You print the temperature once, in setup(); but as you have not read any temperature yet the value will be 0 (global variables are initialised with 0 if not instructed otherwise).

Add a lcd.setCursor and lcd.print to loop after you have calculated TempC..

thank you for all ur help, but now it changed to =-50

You need to post your updated code; and please use code tags when posting code (read the sticky how to use the forum).

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int Tempsensor;
int mV;
int TempC;

void setup()
{
  lcd.begin(16,2);
  lcd.setCursor(1,0);
  lcd.print("Temperature(C)=");
  lcd.setCursor(1,1);
  lcd.print(TempC);
}

void loop()
{
  pinMode(A0,INPUT);
  Tempsensor=analogRead(A0);
  mV=((Tempsensor/1024.0)*5);
  TempC = (mV-0.5) * 100.0;
  lcd.setCursor(1,1);
  lcd.print(TempC);
}

Make mV a float (not int):

int mV;

Please delete post #7, which contains only improperly posted code.

I don't have the sensor, but connected A0 to GND, 3.3V and 5V and get -50, 250 and 350 respectively from your code.

Can't really help further.