RAWALPINDI, Pakistan, May 19-The Chinese presence in Pakistan has become increasingly noticeable as new aid from Peking Is announced, newspapers praise Chinese policies and columns of blue-uniformed Chinese officials march through airport waiting rooms.

Last week China pledged a new interest-free loan to Pakistan of about $20-million bringing total pledges to date of Chinese aid to about 4307-million.

Western officials note that of $450-million pledged over the years to Pakistan by all Communist nations, including the Soviet Union, only about one-third has actually been disbursed.

China's loans to Pakistan, which are repayable in commodities rather than cash, are evenly divided into two categories. The first is to provide the means of buying commodities, especially coal, coke, rice and some raw materials. The second is for various projects.

One of the projects was for an arms factory at Ghazepur, near Dacca, in East Pakistan, employing upwards of 1,500 workers. When massive civil disobedience by Bengali separatists disrupted East Pakistan in March, the plant had to halt production for lack of workers. The Government has since reported that work there has resumed.

The type of equipment manufactured at the plant has not been disclosed, but it is understood to include small arms and ammunition of Chinese design. Some of this equipment was probably used by the army in East Pakistan in suppressing the separatist rebellion .

U.S. AID POLICIES CRITICIZED

Other Chinese projects include a heavy-machinery complex at Taxila in West Pakistan and a 380-mile blacktopped road linking Thakot, West Pakistan, with Sinkiang Province in China.

But the Chinese presence in Pakistan has acquired special significance since the United States suspended aid in March. Newspapers and Government officials daily draw unfavorable comparisons between United States aid policies here and those of China.

When a plane load of powdered milk arrived from China last week, officials pointedly noted that the milk was to be distributed by Pakistani officials themselves without foreign supervision. The United States insists that foreign observers be present when goods are distributed to insure that they are actually delivered to the intended recipients.

A Pakistani official whose views reflect those of the Government recently told an American "If you Americans tell us to go to hell, you must expect that we will turn increasingly to China."

FOOD IS A PROBLEM

Chinese aid to Pakistan dates from 1965, the year Pakistan and India fought a brief war over the disputed Rann of Cutch area. There is a feeling here that the struggle between Pakistan and India has to some extent involved the Soviet Union as a friend of India and China as a friend of Pakistan.

Only South Vietnam has received more American aid than India and Pakistan. Since 1954, Pakistan has received more than 94 billion.

Bengali separatists and others have condemned United States aid as one of the main props of the Pakistani central Government. The Government, on the other hand, has charged that the suspension of aid was a political act motivated by a wish to meddle in Pakistan's domestic affairs.

The presence of uniformed Chinese officials has not gone unnoticed by the local population. And, privately, some Chinese have expressed a certain sense of discomfort at living in Pakistan.

A minor problem is food. Moslem law which is practiced rigidly in Pakistan, precludes the eating of pork. The Chinese miss this and also vegetable cooking oils from home and other specialties.

Pakistan, currently governed under martial law by the army, is not a socialist country. For the most part, the Chinese diplomatically avoid political discussion here. But most experts feel that China will assert a cautious but increasingly important role in Pakistan.