1. Abstract The influence and expansion of Islam religion in the Indian Subcontinent are the important issues which have been considered by scholars for a long time ago. Various factors have contributed to the spread and influence of Islam in the Indian Subcontinent including the arrival of early invaders, Muslim merchants and traders, and the migration of Muslim clerics and Sufis. Meanwhile, the share of Sufis has been higher and more considerable than in other groups. Some Western and Indian scholars believe that Islam first entered the region through military conquests. But, historical evidence did not support this claim. Although in a general process, military movements should be considered as obstacles to the influence and spread of Islam, but in some periods and some areas of migration, military campaigns provided a good platform for groups of Arab tribes or individuals and groups of merchants, Sufis, scholars, and scientists to enter the area. Some Sufis even went to India with the same troops. With proper and humane behavior and interaction with the inhabitants of the Indian Subcontinent and the Indian religions, Sufis were able to partially eliminate the hatred and pessimism of the Indian invaders about the actions of the Muslim invaders in the early periods of the spread of Islam. 2. Introduction The main aim of the research is the expansion of Islam in the Indian Subcontinent with relying on the influence of moral and spiritual behaviors of Sufis especially the reduction of the negative approach of inhabitants and the Indian hatred and pessimism from the function of the invaders in the early period of the expansion of Islam. However, Ghaznavids were of forces which took the most effective steps towards the occupation of India. In the fourth century AH, Sabuktagin first invaded India and took the control of much of the region. A few years later, Sultan Mahmud of Ghaznavid invaded India and targeted India fifteen or seventeen times by the end of his reign. This study seeks to answer the question of how the interaction of Sufis and Sufi leaders with the natives of India, especially their spiritual conduct and avoidance of military behavior, had an effect on the Islamization of the Indian people from the Ghurian period to the beginning of the Gurkhanids. 3. Materials & Methods Generally, using the descriptive-analytical method and based on library resources, this paper aims to study Sufis’ contribution to the Islamization of native Indians during the age of Turk rulers. 4. Discussion of results & conclusion The interaction of Sufi missionaries and leaders and their function has played an important role in deepening Islamic and religious beliefs among the inhabitants of the Indian Subcontinent. In fact, the wider influence and spread of Islam in India, according to evidence and citations, was the result of peaceful, tolerant activities and spiritual and cultural interactions, especially by Muslim Sufis. Sufis’ intellectual commonalities with Hindu rituals and practices, their spiritual conduct, exchanges of Sufi cults with the Hindu rituals and especially their avoidance of military and oppressive acts not only drew the attention of Indians to themselves but also changed the negative attitude of the Indian community towards the military and violent behavior of the early Islamic invaders in the invasion of India. Sufis and Sufi cults which entered India as immigrants or preachers were influential in the mental purification of the natives of this region. The spiritual behaviors of Sufis partly improved the negative consequences of Muslim invasions and changed their attitudes toward Islamic teachings. This greatly influenced the new approach of the people of the Indian Subcontinent to Islam after the military invasion. The Sufi group has shown outright honesty, trustworthiness, and chastity in trade and commerce with the leading business classes of India and other social groups. They were actively involved in supporting the rural part of the Indian Subcontinent. On the other hand, they respected the beliefs of the Indians. In the interval between Ghurids’ domination and the Gurkhanid dynasty, Sufi cults such as Chashtiyya, Suhrawardiyya, Naqshbandiyya, Qāderiyya, and Kubrawiyya along with the Indian rulers, especially the Muslim sultans of Delhi, were considered to be the main causes of Islamization of Indigenous Indian Subcontinent. Sufis’ counseling and assistance to Islamic governments in India such as Gholamshahi, Khalajan, Tughlughiyyan, Sādat dynasty, Lūdi governors, and Syrian kings were effective in spreading Islam in the Indian Subcontinent during these periods. The other results of this study showed that the content of Sufi invitations like an emphasis on monotheism, equality of human rights, humility, and accepting divine morality. and reaching God through helping people and aiding helpless ones had a profound effect on the tendency of the Indians to Islam. Learning different local languages and connecting with different religions and classes of India facilitated the Sufis’ invitation for unity and solidarity, especially since Sufis opposed religious monopoly. Hence, they were able to reduce the violence of the early Muslim invaders to some extent by purifying the souls. The preaching method and lifestyle of Sufis, such as seclusion and abundant worship, corresponded to life and aspects of the principles of Indian philosophy. Therefore, the adversary of Indians with the system of inferiority, religious tolerance, support for religious diversity, simplicity of life, and good relations with the Ghurid Sultans, Mamluks, and Delhi kings were effective in the expansion of Islam in the Indian Subcontinent.